|
########################################################################
|u/pastrufazio - 22 hours
|
|Damn I need more fuel to carry all this fuel
|u/Damnmorrisdancer - 21 hours
|
|That’s Tyranny!
|u/g-rizzle84 - 20 hours
|
|For those that don't get it: [The Tyranny of the
|Rocket](https://en.m.wikipedia.org/wiki/Tsiolkovsky_rocket_equation)
|u/Blake_Bosten - 20 hours
|
|Thanks, I still don't get it
|u/7MileSavan - 19 hours
|
|A rocket has a point of diminishing returns, where it will only
|become exponentially heavier for very little gain in power.
|u/Blake_Bosten - 19 hours
|
|Thanks, I get it!
|u/g-rizzle84 - 19 hours
|
|My bad, I could have added a tldr/eli5
|u/gefahr - 18 hours
|
|Nah people gotta learn to learn.
|u/Akilestar - 19 hours
|
|This applies to modern day electric vehicles as well. It's why
|we don't have EVs with a 1000 mile range. At some point you're
|just adding batteries to have enough energy to carry more
|batteries. Solid state batteries are the answer and are
|currently the only thing that really makes a world with an ICE
|vehicle a possibility. Stop these ridiculous EVs subsidies and
|put the money into that research and we'd be much better off.
|u/speculatrix - 16 hours
|
|Many people talk of range anxiety. What we have is really
|charging anxiety. All you need is enough range to
|guarantee you can drive a comfortable distance to the next
|toilet and coffee/snack break
|u/Akilestar - 15 hours
|
|Solid state batteries solve this problem as well. While
|having almost double the energy density, they can charge
|4x faster. 500 miles (800 km) in 10 minutes solves a lot
|of EV problems. Range, charge time, number of charges
|required per station, and the number of stations.
|u/speculatrix - 15 hours
|
|But how often do you need to drive nonstop? Really? And,
|eventually you'll have to charge.
|u/Akilestar - 14 hours
|
|I'll just go ahead and say I disagree with your
|statement about range anxiety. Everyone complains
|about charge times, if they were faster and less often
|then range is moot. So again, let's stop subsiding
|crappy technology that's no better for the planet than
|ICE vehicles and subsidize a far superior technology
|that's significantly better than both lithium powered
|EVs and ICE vehicles.
|u/TheDaysComeAndGone - 18 hours
|
|Cars are not the solution, no matter the drivetrain. Modern
|EVs also have ~400km range which is plenty. Edit: Oh, and
|we could probably make them go much further if we were
|willing to sacrifice on speed and size and maybe safety
|features.
|u/Akilestar - 15 hours
|
|Considering roughly 20% of the US population live in rural
|areas, cars are absolutely necessary. I'm not discounting
|public transportation but you can't discount the 60
|million people in the US that need reliable transportation
|and for the foreseeable future, cars are absolutely their
|best, if not only option.
|u/TheDaysComeAndGone - 15 hours
|
|Even in the US lots of journeys could be done on bike or
|foot with little to no change/investment into
|infrastructure. Mid-term you could probably add a lot of
|bus lines, if the willingness to use them were there.
|Long term of course you’d need a change in how villages
|and cities are built and how far away people *choose* to
|live from their workplace, supermarkets and other daily
|destinations. It would also help a lot if your typical
|car would be more like a Fiat 500 than a Ford F150. If
|the willingness were there, things could change quite
|quickly and drastically with comparably little cost.
|u/Akilestar - 14 hours
|
|You've clearly never lived in rural America. Maybe you
|should change your views of rural America instead of
|making them fit in your box of how they should live.
|Not everyone wants to live stacked on top of each
|other. You can't walk, bike, or even bus 5-10 miles in
|a foot of snow. You're welcome to figure out how a
|city of 1000 people can bus everyone to work when the
|weather cooperates. And I guess they're just supposed
|to sit at home the rest of the time. You're pipe dream
|of a civilization with no cars is absolutely
|ridiculous. You're typical car is just that, a car.
|Trucks make up less than 20% of "cars" on the road. A
|Fiat 500 costs more than my pickup and I get 20 mpg,
|in the city. A Fiat of the same year gets a whopping
|24 mpg.
|u/bongoissomewhatnifty - 12 hours
|
|Did Shell write this? Counterpoint: modern EVs as they
|work right now today are an acceptable substitute with some
|minor inconveniences for longer trips. They’re not a great
|substitute because the best answer tells us to get rid of
|the fucking cars, but hey. “But they’re still bad for the
|environment!!” Fuck yeah they are champ, good job. The
|selling point is that they’re much *less* bad for the
|environment over their complete life cycle. The selling
|point is not that they will magically heal nature and fix
|everything. “The mining process for lithium is terrible
|and wrecks the earth and uses slave labor in developing
|countries!!!” No it doesn’t. You’re thinking of cobalt;
|which was used in earlier lithium ion batteries but has
|largely fallen out of use in modern batteries - Tesla for
|instance uses cobalt free batteries and has transitioned to
|lithium iron phosphates. Lithium in comparison is not a rare
|earth metal that can only be found in exploitive mining
|practices using slave labor. “There isn’t enough
|lithium!!!” This shit is fucking everywhere. It’s so
|common nobody really ever bothered looking for it before.
|Since its popularity for use in EVs has skyrocketed, huge
|amounts of it are being found all over the world. “Well
|lithium mines are still terrible for the environment!!!” As
|opposed to what? The cleanliness we get from oil drilling,
|fracking, extracting, and transportation and refining? Fun
|fact: that math has already been done, and you will be
|shocked to know that the petroleum industry was not the most
|environmentally friendly option. “Put that money towards
|better battery research instead!!!” Bro…. Just like. Bruh.
|You understand that basically all of the huge battery
|advancements that we’ve been making in the last few decades
|have come from increased spending in these areas right? Like
|where do you think the subsidies are going? If there’s no
|demand for the EVs because they’re too expensive, then
|there’s nobody researching new battery technology. The
|market has been driving advancements in battery research.
|Those subsidies have been supporting that market so that it
|can do it. If there is a collapse in the market for EVs,
|there will be a collapse in battery research and the
|subsidies will in no way come even close to providing a
|stopgap to make up for that loss of funding. Brains. We
|use em for thinking. You should try taking yours out for a
|spin some time and see what that puppy can do instead of
|leaving it parked in the garage idling away.
|u/Akilestar - 11 hours
|
|You made a lot of assumptions off a simple comment. It's
|100% factual that more weight reduces vehicle range,
|batteries are very heavy. At some point you are getting
|less range for the same weight of batteries. Exactly the
|same law from the OP. I never endorsed ICE over Lithium
|batteries. I'm not even sure how you came to that
|conclusion, I guess use your brain next time? I stand by
|my endorsement of solid state batteries over lithium
|batteries, as does science. Since you brought up cobalt,
|you do realize that's the "C" in an LCO battery right?
|Well it is, and it's the most common type of battery in an
|EV. Lithium is absolutely terrible for the environment.
|Over 65% of lithium comes from brine. One tonne of lithium
|from brine emits 15 tonnes of CO2. It pollutes and
|depletes local water sources. They create a massive amount
|of salt waste, it's the same problem desalinization plants
|experience except they just leave it in the lake and
|destroy everything around them. So once again, solid
|state batteries are far superior to lithium batteries in
|every single way except their complexity to be
|manufactured. Why do we need lithium cars for a better
|battery to exist? Last I checked batteries are used in
|thousands of devices. We didn't EVs with lead acid
|batteries for lithium batteries to be invented. And no,
|I don't work for Shell, you'd probably lose your shit if
|you found out my employer.
|u/this1willdo - 6 hours
|
|SS batteries are imaginary. Show me a link where I can
|buy one that matches what you say for a reasonable
|price. “Coming soon” means 10 years of ramp up.
|u/Wendals87 - 10 hours
|
|Basically it boils down to many people not wanting change
|unless it's 100% better in every way I agree with all
|your points after owning my EV for a year and doing a few
|big road trips
|u/retro-embarassment - 1 hour
|
|> The market has been **driving** advancements in battery
|research. I see what you did there
|u/Wendals87 - 10 hours
|
|We don't need EVs with 1000 mile range. (And what ice car
|has that range?) 250 miles (400km) is plenty for the
|majority of people. The average is 13,5000 miles per year
|(21,700km). In Australia, it's only 15,000km a year One
|full charge a week on average is enough
|u/zombiphylax - 20 hours
|
|You need more fuel to go farther up, but then you need more fuel
|to lift that more fuel, and then you need more fuel to lift that
|more fuel, and then...
|u/RocketCello - 19 hours
|
|Ah, the Tsiolkovsky rocket equation and it's tyranny. Change in
|velocity is the effective exhaust velocity times the natural logarithm
|of the mass fraction (wet mass/dry mass). Very nasty exponential
|growth there.
|u/pokethat - 7 hours
|
|That's why I like all the startup companies that try ideas that
|Short circuit the rocket equation by yeeting stuff into space, or at
|least getting them going pretty darn fast before the rocket actually
|needs to use propellant
|u/moogly2 - 19 hours
|
|Yo dawg, I heard u like carrying fuel...
|u/thephantom1492 - 16 hours
|
|Joking appart, this is one of the reason why an airplane may carry
|more fuel out of some airports. They consume so much fuel that if the
|fuel is significantly cheaper in one airport they may fuel up more,
|even if they will consume more fuel, because in the end the extra
|burned is still less expensive than if they would fuel in the
|destination airport.
|u/Asleep_Management900 - 18 hours
|
|that's why planes often don't fly direct because it's much cheaper to
|stop and refuel. Like, Newark to South America might stop in Florida
|and refuel. Flying direct is expensive for that reason.
|u/are2deetwo - 20 hours
|
|Let me introduce you to Emirates airline. The pioneer of more fuel to
|carry more fuel.
|u/Fr3akwave - 19 hours
|
|Rocket science!
|u/OneSalientOversight - 1 day
|
|That's 1 litre every second for each engine. Source: Maths
|u/spakattak - 1 day
|
|Going to need to see the working out on that one.
|u/OneSalientOversight - 1 day
|
|https://i.imgur.com/e2ae6pK.gif
|u/Cosmiccomie - 23 hours
|
|Sorry I see the equation but I'll need you to write out the proof.
|u/UniqueIndividual3579 - 19 hours
|
|Proof: I read it on the internet.
|u/johnthedruid - 18 hours
|
|For real, how many seconds does it take to get anywhere far across
|the world? And there's that many gallons in the plane, per engine?
|Hard to believe but only care just enough to type this and not
|enough to look into it.
|u/doomgiver98 - 18 hours
|
|Just looked it up, OZ283 from San Francisco to Seoul has 11h 14m
|scheduled travel time. That is 40440 seconds. 4L/s is 161760
|Liters of fuel. A Googling says a modern 747 holds over 216,000
|liters.
|u/johnthedruid - 17 hours
|
|Sheeeesh r/theydidthemath
|u/manondorf - 8 hours
|
|ok but what is that in olympic swimming pools?
|u/ModernMuse - 7 hours
|
|0.0647 olympic swimming pools
|u/Impossible_Angle752 - 11 hours
|
|Probably why only Lufthansa flies them any more.
|u/xspiderdude - 19 hours
|
|Source: because I say so
|u/pohl - 1 day
|
|Cruising speed is Mach .85 or around 647 mph. At that speed a 747 gets
|just about 0.18 mpg. But there are 366 passengers aboard. If each of
|them were driving a car, the cars would need to get 65 mpg to be more
|efficient than the 747. If you figure the average passenger is traveling
|in a party of 2, you still need the equivalent of a sub compact to match
|the fuel efficiency of a 50yr old mega plane. I think I did the math
|correctly, maybe not. If so, that is a pretty surprising result to me.
|Edit: couple thoughts after reading some replies: -jets encourage long
|haul travel that would not be done by car. Noted -some 747 configs hold
|up to 660 passengers which nearly doubles the efficiency -nobody drives
|across the Atlantic. Noted I didn’t post this to justify jets. The same
|reason that buses are more efficient than cars also applies to planes.
|It’s not that planes are the solution to carbon pollution, it’s just
|that cars are REALLY wasteful. A quick google shows that passenger cars
|account for 4x the total CO2 emissions of aviation. Cars suck!
|u/Edward_TH - 23 hours
|
|Take into account that a plane also fly almost always full of cargo.
|You would need to account for a full trunk for a car to match the
|math. A 787-9 uses 5600 kg an hour at 903 km/h, so 6.2 kg/100km (1.9
|L/s, about 30.3 mpg) and at 290 seats that's 0.025 L/100km/seat which
|is impossible to match for a car. An A380 would be a better comparison
|so... 12000 kg/h at M0.85 it's ~16.2 L/100km (14.6 mpg) seems quite
|underwhelming, but at the typical 570 seats that's an impressive 0.028
|L/100km/seat, barely over the much more efficient 787-9 but MUCH
|better than the 747 which uses 75% more fuel per km per seat! Planes
|environmental impact is not the fuel efficiency, which is great, but
|the fact that their fuel cycle is much more polluting and it's
|released high into the troposphere. But as always, mass transportation
|is vastly more efficient than personal transportation.
|u/LeptonField - 21 hours
|
|I wonder if discussing a plane’s environmental impact is just a
|thought experiment. It really feels like a technology that is too
|highly prized to ever attempt to curb for environmental reasons.
|u/paranoid_giraffe - 20 hours
|
|That’s because it is. One of my aero professors always used to say
|that if we didn’t end up working in aero then we need to work in
|automotive so we could push non-gas based designs. Making electric
|planes is orders of magnitude more difficult than making electric
|cars, so he’d always say we need to save petroleum based fuel for
|aircraft. The fuel efficiency of a fully loaded aircraft beats
|ground vehicles easily when you consider cargo and passengers, and
|we don’t have anything combustible with the energy density of
|petroleum fuels (yet). That was over ten years ago and obviously
|still hasn’t changed. Also it’s been a while since I did that
|math but I’m pretty sure aircraft ten years ago were more
|environmentally conservative than vehicles of the same time with
|the same passengers and cargo going the same distance. The
|comparison wasn’t even close
|u/Ein_Fachidiot - 17 hours
|
|I'm sure buses, trains, and ships beat airplanes in terms of
|environmental efficiency. They're just slower.
|u/paranoid_giraffe - 15 hours
|
|Trains were close - either barely more or barely less
|efficient but like I said, it’s been a decade since I looked
|at the numbers. I think they were better but not by much. I’d
|have to look at it all again but it’s likely you’re right to
|some extent since vehicles have gotten much more efficient
|just over the last ten years even. Funny thing with big
|vehicles though is that they don’t change much so I really
|don’t know.
|u/fuzzy11287 - 9 hours
|
|You can also electrify train tracks rather than use diesel.
|Idk how well that works for cargo but plenty of passenger
|trains are electric.
|u/AbbaFuckingZabba - 18 hours
|
|The problem isn't the planes, it's the people. It's somewhat
|disingenuous to compare the 747 emissions with all of the
|passengers driving instead, since if planes were not an option
|many of those trips simply wouldn't be taken. Air travel is
|essentially a market based efficient approach to burning fuel to
|go to far places. Like it or not, we have (and continue to)
|artificially subsidize this cost of this fuel and we of course do
|not account for the environmental damage that occurs from it's
|use. It would be much better if the cost of the fuel included
|the environmental effects of it's use and was uniform around the
|world. This would cause a huge reduction in air travel demand and
|increase in costs that would have a positive impact on everyone
|breathing the air.
|u/LeptonField - 18 hours
|
|I don’t share the presumption that the harm of aviation
|pollution outweighs the benefit to humanity. Maybe it does, but
|I don’t expect people to take action on such as presumption
|without extraordinary persuasion.
|u/eairy - 16 hours
|
|> artificially subsidize this cost of this fuel You don't seem
|to understand what the word 'subsidize' means. There is no
|subsidy on air fuel.
|u/FriendlyDespot - 8 hours
|
|Plenty of countries subsidise jet fuel directly in some
|fashion. The United States is directly subsidising SAF to
|encourage migration from Jet-A, and the SAF itself is further
|subsidised through agriculture subsidies for the corn
|feedstock.
|u/AbbaFuckingZabba - 16 hours
|
|Sure there is. Nearly all of the middle eastern countries
|heavily subsidize fuel. It's also common in se Asian and
|Latin America.
|u/eairy - 15 hours
|
|Are you sure you aren't confusing fuel for cars and fuel for
|aeroplanes? I can't find any source that says jet fuel is
|subsidised in any country.
|u/Stingray88 - 14 hours
|
|To play devils advocate… jet fuel comes from oil the same
|way automotive fuel does. And the oil industry is
|absolutely subsidized all over the place. If it weren’t
|for subsidies in oil, the price of jet fuel would surely
|be a lot higher.
|u/China_Lover2 - 2 hours
|
|When are we getting electric planes?
|u/Ein_Fachidiot - 17 hours
|
|I'm an engineering student. We just don't have the technology yet
|for renewable-fuel passenger planes to be feasible. Aircraft are
|very sensitive to weight. None of our batteries can come close to
|the energy density provided by fossil fuels. The intense heating
|of the air provided by combustion engines also helps provide more
|thrust when the air expands out of the back of the plane. I truly
|believe we will get there one day. Perhaps we will have passenger
|airplanes with small modular fusion reactors or highly efficient
|batteries. The tech just isn't read yet.
|u/KingOfLosses - 15 hours
|
|The problem isn’t how inefficient it is. Cars are quite a bit
|worse. But rather how easily we fly a 10000 mile round trip. It’s
|just 2 flight say from chicago to Rome. That’s a yearly car
|useage for just a vacation. That’s where the issue lies.
|Especially for people who do this type of flight several times a
|year either for vacation or business.
|u/SuperFluffyArmadillo - 8 hours
|
|It's not! The international commercial aviation industry is very
|interested in finding ways to reduce its environmental impact.
|https://cascade.boeing.com/
|u/mybeatsarebollocks - 19 hours
|
|And that is why we are still accelerating towards ecological
|collapse......every aspect of our lives and technology are too
|highly prized to attempt to curb for environmental reasons. "We
|need drastic change to avoid hitting 1.5°c warming of the planet!"
|"We've reached 1.5°c of warming....we need drastic action to avoid
|hitting 3°c......." Still nothing.......perhaps cut down on meat?
|We're so fucked.
|u/LeptonField - 18 hours
|
|What in the false equivalence are you yapping about. Obviously
|all technology is not equally important.
|u/cheesenachos12 - 18 hours
|
|Yeah, but like... trains could easily replace a lot of
|short/medium length flights at 1/20th the emissions or so
|u/thetimsterr - 18 hours
|
|You should take a look at JetZero. Their new plane design is
|supposed to be 50% more fuel efficient, which could be a huge game
|changer. Part of the problem is we're using the same plane design
|from 70 years ago. JetZero is trying to rethink that.
|u/LeptonField - 18 hours
|
|It’s a nice thought but, I try not to get my hopes up on things
|still at that stage. Too many grifters out there.
|u/soulsssx3 - 19 hours
|
|That's assuming full cargo, though. I think criticism comes in from
|people when the 1% are using private jets by themselves. It's
|probably a drop in the bucket compared to industrial impacts, but
|the optics don't look good
|u/AFineDayForScience - 21 hours
|
|We could also take into account that if we didn't have planes, most
|of the people decide the drive isn't worth it and stay home lol
|u/swaminasibami - 16 hours
|
|Just pointing out some of your calculation seems off. 12000 kg/hr at
|900 km/hr equals 12000 kgs per 900 km, ergo 13,3Kg/km for the plane,
|or 1330Kg/100km which is a few orders of magnitude greater than your
|calculation. With 570 seats this makes 2,34 kg/100km/pax. Which is
|still better than a car, but at the same order of magnitude.
|u/3MATX - 19 hours
|
|The contrails have a big effect too on the atmosphere. The change in
|US temp daily fluctuation is seen in the days following 9/11 with
|zero civil planes over US.
|u/TheDaysComeAndGone - 18 hours
|
|> Planes environmental impact is not the fuel efficiency, which is
|great The problem is that planes travel long distances. Few people
|drive 10Mm to their holiday vacation, but take a flight from Vienna
|to Tokyo and you are covering more than 9Mm and emitting ~200g CO2e
|for every kilometre travelled. Cars are still bad, many people
|drive more than 20Mm per year and making a car emits several tons of
|CO2e on its own.
|u/doomgiver98 - 18 hours
|
|Are you using M as the shorthand for thousand? Edit: Megameters?
|u/TheDaysComeAndGone - 17 hours
|
|SI-Prefix Mega. Just like kilo, milli, micro, nano …
|u/really_random_user - 1 day
|
|Did the math for an a320 And came to about 4l/100km /pax Which is also
|close to what a car with a single passenger uses
|u/beirch - 1 day
|
|4L/100km is a very economic car, not exactly average.
|u/RexPerpetuus - 1 day
|
|In Europe, cars like that aren't as uncommon. My 17 year old
|diesel car does 5L/100km
|u/DiddlyDumb - 23 hours
|
|Europe has passed a lot of strict emission rules in the early
|2000s, to the point where manufacturers complained it was
|physically impossible to make cars that reach those numbers.
|Now every car matches those demands with ease. Apart from a few
|Volkswagens of course…
|u/RexPerpetuus - 23 hours
|
|Yea, my car was a victim of that. Engines with DPFs and EGRa
|and other devices that choked em out, essentially. Also just
|putting more points of maintenance and reliability issues on
|the end consumer.
|u/AVgreencup - 22 hours
|
|Yes, but before it was the consumer putting the stinking
|soot filled air on other people. I'm ok with diesel drivers
|losing a bit of efficiency for the sake of emissions
|u/RexPerpetuus - 22 hours
|
|Besides the underestimation of "losing a bit of
|efficiency" (it completely ruined some car
|engines/required super costly maintenance so you might as
|well toss the car), the shift to diesel came about when
|governments created incentives to buy these cars as "more
|environmentally friendly". The crappy end of the stick
|would rear it's ugly head a few years later, again,
|hurting the end consumer
|u/AVgreencup - 21 hours
|
|Anyone who thought they were environmentally friendly
|was so naive it's unfathomable. One smell of the air
|behind an untreated diesel vehicle, one look at the
|black smoke it makes, should be enough to know. Plus,
|we've known about NOx emissions causing smog for over 40
|years, no excuses. Don't think of it like they lost
|efficiency by adding emissions equipment. Think of it
|like that's the only way it's supposed to be. Just like
|catalytic converters on gasoline cars. They add cost and
|complexity and initially they were terrible, bogging
|down efficiency and plugging. Now they're essential to
|us having the clean air we do have
|u/FiddlerOnThePotato - 20 hours
|
|The major issue I take with how diesel emissions
|controls are implemented is mostly with EGR. It's hell
|on the engines. It cakes everything in the intake path
|with that nasty soot that used to come out the back.
|The reason I take so much issue with it is that it's
|possible with modern tech to design an engine without
|EGR that still meets emissions, but it's my
|understanding that EGR is legally required. And if it
|were like cats where we improved them to where you can
|have a super high flow cat that's barely a
|restriction, that'd be one thing, but brand new
|diesels are dying by 100k due to EGR gasses depositing
|coke and destroying turbos and intake valves. And I
|don't think it's farfetched to say we should consider
|the lifetime of a vehicle into its environmental
|effect. If a truck is built that lasts 400k miles and
|pollutes more, that might still offset the
|improvements made with a new truck if you have to
|build four of them to make it the same distance.
|That's materials, labor hours, shipping, and those all
|have an effect too.
|u/RexPerpetuus - 20 hours
|
|> Anyone who thought they were environmentally
|friendly was so naive it's unfathomable. One smell of
|the air behind an untreated diesel vehicle, one look
|at the black smoke it makes, should be enough to know.
|Plus, we've known about NOx emissions causing smog for
|over 40 years, no excuses. People bought them because
|they were cheaper, they were *incentivized*
|economically by the government and this "new"
|generation of diesel vehicles were touted as an
|environmentally friendly alternative. I wasn't trying
|to convince anyone that the people as a whole was very
|environmenttally friendly, and none of my comments
|suggest that > Don't think of it like they lost
|efficiency by adding emissions equipment. Think of it
|like that's the only way it's supposed to be. Just
|like catalytic converters on gasoline cars. They add
|cost and complexity and initially they were terrible,
|bogging down efficiency and plugging. Now they're
|essential to us having the clean air we do have
|Again, they didn't simply "lose efficiency". They gave
|many of the cars limited lifetimes, almost planned
|obsolescence in a sense. That's *not* environmentally
|friendly or friendly to the working class who were
|buying these vehicles. EDIT: /u/FiddlerOnThePotato
|has honestly put the technical aspect of this as
|succinctly as possible [in his comment](https://www.re
|ddit.com/r/todayilearned/comments/1gskvah/til_a_boeing
|_747_uses_4_litres_1_gallon_of_fuel/lxg248d/)
|u/LikesBallsDeep - 20 hours
|
|It's almost like governments make lots of mistakes and
|them trying to put their thumbs on the scale to push
|certain technologies is bad.
|u/Daefish - 23 hours
|
|As an American, I can’t relate. I can however offer you a 3
|meter tall truck that belches black smoke and goes no less
|than 12 yee-haws per kilometer. It’s an up charge though for
|the giant bolt on American flag
|u/DiddlyDumb - 22 hours
|
|Wtf is a kilometer?
|u/koosley - 22 hours
|
|I think OP meant kill-o-meter. It just measures the gun
|deaths in the US. For some reason ours is high and we
|can't figure it out.
|u/PFirefly - 20 hours
|
|Gangs mostly. Its not a mystery.
|u/ZAJPER - 16 hours
|
|Or guns
|u/SenTedStevens - 14 hours
|
|That's what drug dealers use to measure narcotics.
|u/Captain3leg-s - 21 hours
|
|Opposite of a freedom unit. (i.e. Imperial) A mile.
|u/treefox - 20 hours
|
|> a freedom unit A penis?
|u/rtothewin - 21 hours
|
|Us planet conscious truck bros with our lifted 3.5 eco boost
|can’t relate to the smoke. Tsk tsk
|u/SaltyBalty98 - 23 hours
|
|I wouldn't say with ease. Nowadays they drink more oil, wear
|out faster, require more maintenance and parts replacement,
|and are somewhat underpowered for the platforms they're put
|on, this is especially true with the 3 cylinder engines being
|used in the larger and heavier compacts.
|u/mobettastan60 - 21 hours
|
|but those few VWs you speak of got great mileage...lol
|u/Leemesee - 21 hours
|
|My 2015 golf does 4,5l/100km. When driving sith wife, 2,25l per
|person per 100km. It’s half the cost of taking a public
|transport and 3 times as fast where I live.
|u/h1nds - 21 hours
|
|Apart from Smart FroTwo’s diesel cars and some very old diesel
|natural aspirated diesels(namely PSA engines) there is no car in
|Europe today equipped solely with an internal combustion engine
|that gets 4L/100kms. Hybrids can do it in city driving but the
|long term average on normal usage will be higher than that(the
|average will rise a lot with highway driving, the hybrid
|Achilles hill).
|u/liberovento - 21 hours
|
|My v40 did that, my ford fiesta still doing that, my grande
|punto was really close to that before falling to pieces xD
|u/h1nds - 21 hours
|
|No they didn’t. Maybe the onboard computer showed those
|numbers, but in real numbers the fuel consumption was
|probably 0,5 to 1 L higher.
|u/liberovento - 21 hours
|
|Mate, i was uaing sprintmotor and registering every fuel
|and every km at the time, If you dont go aleays 130km/h
|and just go to 110 you will see an enourmous difference in
|fuel consumptio
|u/h1nds - 21 hours
|
|You know that when we talk about average numbers like
|the ones we are talking about in this post is always
|with the “median” in mind, of the normal use of most of
|the users. A plane could also consume less fuel if
|they turned their engines “100kms” before arriving at
|the destination and just free fly the rest of the way
|and save tons of fuel, it’s possible to fly this way and
|to get better fuel mileage this way but is it the normal
|use? No. Is it the norm for people to go 20kph slower
|than the limit on highways? It is not. Is it the norm
|for people to coast into a stop sign or red light
|instead of being on the gas up until the last moment
|they need to start breaking? No it is not. Is it normal
|for people to not use the A/C to save fuel? Also not.
|This are three examples of fuel saving practices that
|work but don’t make it into the normal routine of most
|people and therefore should not be taken into account
|when talking about fuel average. The same way a dude
|that is flat out all of the time and gets 10L/100kmh
|doesn’t matter to the average fuel consumption of said
|model. I’m not trying to get you in the specifics, but
|talking about average mileage and pointing out you do a
|very specific thing that isn’t at all apart of the
|average driver’s practices doesn’t make sense.
|u/RexPerpetuus - 21 hours
|
|I will not argue, my point was really about that being an
|achievable consumption and seen as less "impossible" over
|here. and we've had cars for years with close to that
|consumption. Hybrids, as you say, depends entirely on how you
|drive it. My mother drives her hybrid to and from work 90% of
|the time, and only has to fuel when she deviates. That said,
|with a very quick Google search I was able to find that in
|2017 at least the Peugeot 208 and 308 and Ctroen C4 platofrms
|(constituuting about 6 models, including Volvo, Nissan and
|Renault branded cars were sold in my country with claimed
|~0.33L/100km. Those are VW Golf sized cars
|u/h1nds - 21 hours
|
|That’s the thing, claimed fuel consumption values always
|come out way too optimistic (for marketing reasons of
|course). In normal circumstances, for 99% of drivers, the
|fuel consumption will be way higher that the advertised
|value. And we can’t trust our onboard consumption values
|neither, they are usually wrong at least 0,5L to 1L if you
|do the math from refill to refill quantity compared to
|driven distance.
|u/RexPerpetuus - 19 hours
|
|They usually aren't that overblown, in my experience. I'm
|sure they won't do 0.33, but 0.4x? Wouldn't surprise me in
|the slightest. The sources I saw after a quick googling
|(self reporting databases, obviously not perfect) are
|looking like ~60mpg+/~0.4 l/100km. Also found a [test
|drive](https://youtu.be/oNhHASzJLd4?si=hENkgrxb_3ik1hbQ)
|of a Peugeot of a larger variety (3008) from 2022 with a
|1.5 liter diesel engine and a result of 0.43l/100km from
|combined driving. The power train should be either the
|same or a related one. Edit: forgot a word
|u/waxstaff - 16 hours
|
|The smaller engined diesels can do that. My mates golf gets
|over 70mpg if he chills at 55mph no problem. My shitty old
|1.9tdi would get 50mpg at 60-70mph with no 6th gear
|u/Rinaldi363 - 6 hours
|
|My pickup does 15l/100km
|u/heffeque - 23 hours
|
|You'll have to explain that diesel engines have been used in
|Europe for normal cars, such as a VW Golf. People in the States
|think of trucks and tractors when they think of diesel engines.
|u/GooginTheBirdsFan - 23 hours
|
|Acting like Americans don’t know what a TDI is has me weak
|u/jeepsaintchaos - 23 hours
|
|Sounds like a disease, but the doctors too expensive for
|that.
|u/sh1boleth - 21 hours
|
|There was a whole scandal here involving a certain German
|car company for the people cheating on their diesel
|emissions, diesel was effectively dead in the US for
|compact cars after that
|u/beachedwhale1945 - 21 hours
|
|For Americans, that’s 58.8 miles per gallon, which in my
|experience is extremely economical. My car gets about 31.5 mpg
|(7.5 l/100 km), which is a bit above average in the US.
|u/kinky-proton - 20 hours
|
|4/5 is normal for most cars unless bad driver or huge engine
|u/beirch - 20 hours
|
|Exactly, you managed 3.6L in a *very* economical car. I live in
|Europe as well, and 4L/100km is not realistic for most cars.
|Even if you're *only* driving on highways, something like 6 or
|7L/100km is more realistic.
|u/Edward_TH - 18 hours
|
|Nah, most new cars can hover just below 5 with really minimal
|effort. If you go for a slow run you can go below 4 with most
|cars from the last 5 years. My SO has an hybrid Panda and she
|drives very aggressively, yet she is at 4.1 average; when I
|drive it I'm very relaxed and hover around 3.6. My 2018 model
|Sandero has a comfortable 4.7...
|u/ToineMP - 23 hours
|
|And if that car went anywhere close to 500mph it would burn much
|more fuel
|u/Unumbotte - 16 hours
|
|You'd probably get a ticket too.
|u/old_righty - 22 hours
|
|You responded to a post using freedom units with some kind of alien
|measurement system.
|u/newstenographer - 20 hours
|
|Fuel efficiency is going to scale non-linearly with pax capacity,
|because the extra weight doesn’t slow the plane very much. Ie, a
|large plane is always going to be more efficient than a small plane
|per passenger because most of the work is acceleration not lift
|(lift is basically free).
|u/SinkHoleDeMayo - 19 hours
|
|I've done thr math for the A320/A321 (but have been the newer neo)
|and it's roughly 100mpg per seat. That's triple the efficiency of a
|smaller car.
|u/BrainOfMush - 18 hours
|
|The A321XLR is even more efficient (+ longer range, bigger fuel
|tanks).
|u/Tommich - 17 hours
|
|But it stays roughly the same for 5 people. So it would be around
|1.5l/100km for a full car. With electric cars, it’s around 5-10
|kWh/100km/pax, which equals around 0.5l/100km/pax
|u/RustyWinger - 11 hours
|
|It’s amazing how relatable this is when you change it From mpg to
|l/100
|u/Benyed123 - 23 hours
|
|Also planes take more direct routes so end up travelling a shorter
|distance.
|u/eatingpotatochips - 20 hours
|
|Planes are cheaters and travel in an extra dimension.
|u/TheDaysComeAndGone - 18 hours
|
|Lots of time they don’t go in a straight line. Plus, they go up and
|down which adds vertical distance. Usually the airport is also quite
|a bit away from your actual source/destination.
|u/ComradeGibbon - 1 day
|
|You're basically correct. Aircraft are actually really efficient. The
|problem is it's way easier to travel vast distances in an aircraft
|than driving a car. For about ten years in the 80 and 90's I flew
|every two months. Probably 400,000 miles. And average of 100 miles a
|day. Just flying.
|u/muyapuya - 22 hours
|
|The industry metric you may be interested in is Cost per Available
|Seat Mile (CASM). It's the cost to fly 1 seat 1 mile. It's usually
|less than 10 cents.
|u/FiTZnMiCK - 1 day
|
|But if they all carpooled in groups of at least two they’d only have
|to get a good, but totally achievable 33 mpg with this math. I think
|the car option breaks down once you consider time savings though.
|Electric planes when?
|u/RexPerpetuus - 1 day
|
|It also breaks down when you have to cross the Atlantic or something
|u/FiTZnMiCK - 1 day
|
|Just get an [amphibious exploring
|vehicle](https://m.youtube.com/watch?v=dNc7FEJmBZ0).
|u/shartonista - 22 hours
|
|Somebody please do the math for a sea passenger ship and an
|airship.
|u/amcrambler - 20 hours
|
|Flying with or against that jet stream greatly affects those
|figures.
|u/RockDoveEnthusiast - 21 hours
|
|But Musk said Teslas would work as a boat!
|u/thiney49 - 1 day
|
|>Electric planes when? Probably never, at least for long haul
|flight like this. Not unless battery energy density skyrockets. IMO
|hydrogen fuel cells make more sense for jets.
|u/koosley - 21 hours
|
|Hydrogen has the same energy per kg as regular gasoline, so it
|probably comes down to being able to store it at a reasonable
|weight. These alternate fuels to me seem ideal to replace the
|45-90 minute flights connecting 2nd tier cities to the
|international hub. There are a few small electric planes in
|testing phases right now and it seems more practical to transport
|50 people a few hundred miles than 300+ people 6000 miles. We may
|get there but it seems a bit early to ever consider that.
|u/Unumbotte - 16 hours
|
|Just put in overhead catenary wires.
|u/ToeKnail - 1 day
|
|Don't count out new battery tech just yet:
|[https://arstechnica.com/science/2024/03/next-gen-battery-tech-
|reimagining-every-aspect-of-
|batteries/](https://arstechnica.com/science/2024/03/next-gen-
|battery-tech-reimagining-every-aspect-of-batteries/)
|u/thiney49 - 1 day
|
|I hope I'm wrong, but I'm not optimistic. There have been
|thousands of breakthroughs that never left the lab. Once we get
|something to production, then I'll start to believe.
|u/ToeKnail - 1 day
|
|The incentives for breakthru battery tech are really at their
|peak right now. Solving storage solutions to pair with solar
|and wind power is where the R&D money is going and once that
|tech is made commercial, scaling for air transport
|applications will happen. We're a lot closer than you think.
|u/thiney49 - 1 day
|
|Like I said, I hope you're right. The only thing that is
|going to change my perspective is actual proven progress and
|results. I need to see the 1000 mile car roll off the
|assembly line before I'll believe any of the hype.
|u/nalc - 22 hours
|
|Well, the peak was probably about 2 weeks ago
|u/sofixa11 - 23 hours
|
|> Godavarthy’s customers are looking to have a higher energy
|density and a faster charge, he said. They are also looking for
|batteries that are relatively less flammable. The new process
|increases the energy density of the battery on a weight basis by
|a factor of two. It increases it on a volumetric basis by a
|factor of three Yeah, for batteries to be viable in long haul
|flying both need to increase by a factor of 10-20, so nowhere
|near close to being enough. https://youtu.be/VNvzZfsC13o
|u/stanolshefski - 1 day
|
|You’re never going to see electric planes on the routes that 747s
|have been flying for the last 40 years. Those long-haul routes just
|wont work with batteries. When battery airplanes get introduced
|commercially, it will be the shortest routes and smallest planes
|that see them first. They’ll also need to be able to do battery
|swaps very quickly.
|u/Jaggedmallard26 - 20 hours
|
|The main reason being that a jet aircraft gets lighter as it
|travels which has a pretty massive impact on efficiency and
|maximum takeoff weight. An electric plane has to lug around the
|depleted batteries for the entire trip.
|u/ChonkTonk - 2 hours
|
|Just drop them in the ocean (just like you should do with your
|car batteries)
|u/DiddlyDumb - 23 hours
|
|And the car needs to get in and out of cities which requires a lot
|of braking and accelerating, but that’s kinda offset by the plane
|having to climb to cruising altitude first.
|u/Jaggedmallard26 - 20 hours
|
|It is always more efficient for a plane to climb as high possible
|and then mostly glide down. If the atmosphere extended infinitely
|the most fuel efficient route would be to climb until it's time to
|descend with the engines on idle. The climbing is
|counterintuitively a positive for jet efficiency.
|u/Steelhorse91 - 23 hours
|
|33mpg at 400+mph? I highly doubt any cars going to achieve that.
|Then there’s all the tyre and brake dust particulates (planes only
|emit these at the airport, not the whole length of the journey).
|u/fourleggedostrich - 1 day
|
|33mpg is "good" Tell us you're American without saying you're
|American!
|u/Federal_Patience2422 - 23 hours
|
|TBF American mpg equates to 40 UK mpg
|u/fourleggedostrich - 22 hours
|
|Still not good.
|u/Hog_enthusiast - 23 hours
|
|That’s miles per gallon not meters per cigarette or whatever unit
|you guys use
|u/fourleggedostrich - 22 hours
|
|My car does 58 miles per gallon. 33 isn't good.
|u/nuggolips - 20 hours
|
|railroad travel is even more efficient than flying on a per-passenger
|basis, by a lot.
|u/scienide - 1 day
|
|Somewhat interestingly, an A380 burns at 11400 l/hr or 3.1 litres per
|second. I think the new A321 may be close to 2 litres per second.
|u/Hog_enthusiast - 23 hours
|
|My car would also get terrible mileage in the Atlantic Ocean
|u/NomosAlpha - 20 hours
|
|These are the stats the average person needs to see in terms of their
|position against one or two people chartering a jet. The average joe
|taking a flight and taking a holiday is not the problem. If you ever
|feel guilty about your consumption under capitalism look UP. YOU are
|not the problem. You are not to feel guilty. YOU are not the problem.
|YOU are being made a scapegoat. The wealth of the 0.01% depends on
|your labour and your guilt.
|u/ItsSevii - 21 hours
|
|Yeah that beats my 10L/100km
|u/koolman2 - 21 hours
|
|A pilot on a flight I took a few years ago did this math and read it
|off to us as we were taxiing to the gate. On that particular flight it
|came out to about 30 mpg (7.8 L/100 km). This was on a 737-900 if I
|recall correctly.
|u/DiddlyDumb - 23 hours
|
|You’re off by one thing, the amount of people that can fit in a
|747-400 (not sure how much seats are filled on average) is 660. So
|you easily need to get over 100mpg per person to match that in a car.
|u/comptiger5000 - 21 hours
|
|That's the maximum number of (very uncomfortable) seats you can
|legally install in one, but the vast majority of real-world airline
|configurations had less seats. Typical configurations were closer
|to 350 - 400 seats.
|u/DavidBrooker - 17 hours
|
|I believe the only high-capacity 747 configurations ever ran were
|domestic Japanese flights, and essentially never internationally.
|It's kinda wild the travel volume between Tokyo and Osaka: even
|with high speed trains leaving every *eight minutes*, there was
|still enough demand left over for JAL and ANA to *each* run 747s
|domestically between the two cities.
|u/brucecaboose - 21 hours
|
|Which is actually very easy with modern EVs. Many get the equivalent
|of 100mpg+ with 1 person in the car. Throw a second or 3rd in there
|and they’ve basically become the most energy efficient way to travel
|medium/long distances.
|u/furryscrotum - 1 day
|
|Although people would never undertake such journeys with a car and
|would ultimately use significantly less fuel as a result.
|u/markzuckerberg1234 - 1 day
|
|True, the fuel consumption is 0 if you dont go anywhere
|u/Cajum - 1 day
|
|No they would take a coal powered steam boat for those journeys
|instead - though if you stuff enough people on one, it might not be
|as bad? lol
|u/Fetlocks_Glistening - 1 day
|
|Nothing wrong with sails
|u/Cajum - 1 day
|
|That feels a lot like replacing cars with horses to save on Co2
|u/respectfulpanda - 20 hours
|
|I’d do it
|u/raspberryharbour - 20 hours
|
|When you're done with your horse you can always eat it -
|tastes much better than a written off car
|u/KnarkedDev - 20 hours
|
|Time. Sailing is vastly slower than powered ships, and more
|limited by weather.
|u/friendlyfredditor - 1 day
|
|Huh? I definitely do... Sometimes you wanna bring stuff to see
|relatives, sometimes you wanna go camping, sometimes you just wanna
|fly instead. You can drive 2000km and still be in the same state in
|Australia. The US is arguably more road trippy. Driving is
|definitely less economical because you can't drive as the crow
|flies.
|u/Hog_enthusiast - 23 hours
|
|Yeah if we view human mobility as a bad thing for a form of
|transportation then planes are worse. What?
|u/furryscrotum - 22 hours
|
|Mobility in itself it not necessarily bad, but humanity should
|consider environmental impact when choosing our destinations. A
|large portion of long-distance travel is not necessary, especially
|not at the cheap levels of airlines. That we could doesn't
|mean we always should.
|u/smokeymcdugen - 21 hours
|
|I don't know about you, but I don't know anyone who travels
|across the country for no reason at all.
|u/RealUlli - 1 day
|
|Why? Just to make planes look bad? Long version: People don't
|want to spend hours on the plane, they want to go somewhere. The
|time is something that needs to be endured because the plane
|doesn't go any faster. Planes spend the time because it's the
|minimum time to reach their destination. On a trip across the
|US, you spend several days driving your car. The plane gets you
|there in a few hours. To get to the destination, your car would
|burn much less fuel per hour but take many more hours to get
|there. So, what exactly is more fair? And no, spending hours
|joyriding doesn't count (unless you're rich enough to do so in a
|747, in that case, you're just an ahole)
|u/BlackPignouf - 23 hours
|
|Because for a weekend or vacations, you don't compare the same
|distances when thinking about planes, trains and cars. But the
|time you'd be ready to travel would be approximately the same.
|And yes, planes objectively look bad when talking about climate
|change or our dependence on fossil fuels.
|u/rinseaid - 1 day
|
|Liters of fuel per hour per passenger might be an appropriate
|comparison.
|u/threebillion6 - 23 hours
|
|Now what about private jets? Lol
|u/DevilYouKnow - 23 hours
|
|So we should fly to work. Noted.
|u/Myrealnamewhogivesaf - 22 hours
|
|Do the math for tankers and container ships
|u/sneakysneak12 - 22 hours
|
|Can someone explain how a plane can carry all that weight and still
|fly?
|u/tommyc463 - 21 hours
|
|The fuel efficiency of a Boeing 747 at cruising speed varies depending
|on the model, but generally, it ranges from 0.15 to 0.25 miles per
|gallon (mpg). However, this figure refers to the fuel efficiency per
|gallon for the entire aircraft, not per passenger. If you break it
|down on a per-passenger basis, assuming a typical load of around 400
|passengers: Boeing 747-400: Around 90 to 100 mpg per passenger.
|Boeing 747-8: Slightly better, at about 100 to 105 mpg per passenger.
|u/chadwicke619 - 21 hours
|
|Did that same Google search tell you how much CO2 consumer travel in
|passenger cars contributes overall?
|u/peeniebaby - 20 hours
|
|Yes but a study could be done to estimate how many fewer people would
|actually drive 1,000 miles away for a weekend trip to go to their
|cousin’s wedding.
|u/amcrambler - 20 hours
|
|A 747 can’t get me to the grocery store, the post office and work.
|u/V_wie_V-Mann - 20 hours
|
|Maybe we should only give rich people the privilege to drive cars.
|u/Gr33nJ0k3r13 - 19 hours
|
|50mpg so 4.3 liters in a car ? Not only is that managable but also you
|calculated probably no waiting time and no waiting laps before landing
|permisssion, i‘m pretty sure a modern jet engine is more efficient
|than just 4.3l liters BUT you waste fuel running the engines to have
|electricity and dealing with the fact that you need to shuffle hundred
|of jets through 2-6 runways. Jets only work at scale and scale is
|exactly whats bad for the envoirenment.
|u/PurepointDog - 19 hours
|
|Now do the math with modern airline economics, considering that many
|of the seats are often empty
|u/davesoverhere - 18 hours
|
|Freight trains are even more ridiculous fuel efficient despite having
|a shit mpg. The trick is they’re hauling a fuckton of goods.
|u/AndroidUser37 - 18 hours
|
|> Cars suck! I dunno man, from your math it sounds like my 6 person
|family road trip for Thanksgiving, in a 25 mpg diesel Suburban, kicks
|the crap out of aircraft as far as fuel efficiency and carbon
|friendliness. And then, if I were to solo daily drive a Model 3 for my
|commute, that's >100 MPGe (yes I know electricity isn't 100%
|comparable but as far as absolute amount of energy used, it wins by
|far).
|u/Training_Ad_2086 - 17 hours
|
|>Cars suck! Mostly stupid american culture where each person in the
|family has their own car with space for 4 people but always drive
|alone and use it for daily commute through traffic jams. Asians
|typically use motorcycles or mopeds for short distance travel like
|daily commute unless there are more people.
|u/John3Fingers - 17 hours
|
|The high-density 747 configurations are actually used a lot for
|shorter-haul domestic routes in China and Japan - yes Japan, despite
|their rail network, and in the Middle East during pilgrimage flights
|to Mecca. There are basically no long-haul routes where that much
|density makes sense both for fuel/range issues and simple economics.
|The world's longest flight, New York to Singapore, is an all-premium
|configuration with just business and premium economy.
|u/0melettedufromage - 15 hours
|
|Ok- now do a cruise ship.
|u/Troy64 - 14 hours
|
|They also travel more efficiently by moving in straight lines rather
|than following roads. The speed is also their air-speed. If they
|travel with jetstreams, which they do as often as possible, they
|travel even faster. Trains are still probably better, but the
|infrastructure and up-front cost and maintenance for the tracks make
|it a smaller difference than most would expect.
|u/mortales_the_one - 14 hours
|
|Boats sucks!
|u/jedielfninja - 13 hours
|
|Big part is terrain flux and climate. Flying across Colorado in winter
|vs driving i40 has a huge value boost compared to driving the same
|distance but in Texas across i10.
|u/NorthSouthWhatever - 3 hours
|
|I love this. I just wish people were more aware of how much congestion
|and noise pollution is caused by their need to often drive alone
|everywhere.
|u/WetPuppykisses - 3 hours
|
|"nobody drives across the Atlantic" Source?
|u/Maelorus - 22 hours
|
|Planes don't need justification.
|u/ePrime - 21 hours
|
|Neither do cars
|u/Maelorus - 21 hours
|
|True. We can and should do both, if perhaps more sustainably.
|u/edthesmokebeard - 22 hours
|
|Dont apologize.
|u/Grom8 - 21 hours
|
|Trains...
|u/poo-ass - 18 hours
|
|Planes...
|u/McWeaksauce91 - 20 hours
|
|How much fuel do boats use? If jets didn’t exist, people wouldn’t just
|stop traveling across the oceans - it didn’t in the past.
|u/theriverrr - 1 day
|
|False equivalent for environmental impact. Jet fuel vs gasoline
|engines. Jet engines are far more harmful to human health and the
|atmosphere.
|u/xXCrazyDaneXx - 23 hours
|
|And you've got a source for that? Burden of proof for claims and all
|that...
|u/theriverrr - 18 hours
|
|https://fivethirtyeight.com/features/every-time-you-fly-you-trash-
|the-planet-and-theres-no-easy-fix/
|u/xXCrazyDaneXx - 18 hours
|
|And nowhere in that... summery/opinion-piece is there any
|evidence for your initial claim that jet exhaust is "far more
|harmful". Besides, when have lobby-groups become objective
|research institutions? I seem to have missed that change...
|u/YOURE_GONNA_HATE_ME - 23 hours
|
|False
|u/theriverrr - 18 hours
|
|https://fivethirtyeight.com/features/every-time-you-fly-you-trash-
|the-planet-and-theres-no-easy-fix/
|u/denied_eXeal - 23 hours
|
|Is it because they can melt steel beams?
|u/Over_Solid_424 - 1 day
|
|It’s double that when your mum is onboard
|u/CapytannHook - 1 day
|
|And say goodbye to the clutch
|u/probablyaythrowaway - 18 hours
|
|Jesus try finding the biting point in a 747.
|u/Huge-Advantage7838 - 1 day
|
|As if...more like treble.
|u/DeusExHircus - 22 hours
|
|Is there a music joke in there somewhere that I'm missing or do you
|have no idea what you're talking about?
|u/Toilet_Bomber - 20 hours
|
|“Treble” can also mean “to triple something”, usually used in
|British English more so than American English.
|u/CapytannHook - 1 day
|
|A Boeing 777 burns 500kg of fuel on the taxi alone. It uses 4 and a half
|tonnes just getting to cruising altitude. But that's nothing compared
|to rockets The Space x super heavy holds 3400 tonnes of fuel, the
|majority of which is used within 160 seconds of launch. Almost 10 fully
|loaded B777s worth of fuel in less than 3 minutes....
|u/gamingchicken - 21 hours
|
|Hope they have a Costco card
|u/trade-guy - 20 hours
|
|You understand super heavy isnt burning jet fuel right? Super heavy
|uses liquid methane and oxygen… a little different than a mixture of
|hydrocarbons…
|u/nnbj92 - 19 hours
|
|Methane is a hydrocarbon
|u/Freeballin523523 - 17 hours
|
|Womp womp....
|u/light24bulbs - 18 hours
|
|I mean even if you look at falcon 9 which uses kerosene which is
|very similar to jet fuel, and you take out the oxidizer, it's still
|a crazy number. I don't know what it is but I'm just saying it's not
|really apples to oranges so much, they both burn fuel
|u/Unumbotte - 16 hours
|
|Alright you've convinced me, for my next flight I won't take a rocket.
|u/TheLizardKing89 - 1 day
|
|Amateurs. -Concorde
|u/JustCopyingOthers - 22 hours
|
|The accident report for the one that crashed in France showed it
|burning about a ton of fuel taxiing from the gate to the runway.
|u/Altruistic_Door_8937 - 20 hours
|
|In my airframe we budget the same amount of fuel to start engines
|and taxi to lineup (before takeoff). It’s not that insane of a
|number in the aviation world.
|u/_xiphiaz - 13 hours
|
|Is there a good reason planes aren’t towed to runway lineup?
|u/Altruistic_Door_8937 - 12 hours
|
|Tons. Tugs are slow. Tug drivers aren’t equipped with radios nor
|trained to operate within the controlled movement area. Airports
|aren’t equipped to deal with a ton of tugs of any taxiway.
|u/ChonkTonk - 2 hours
|
|Tugs actually can go into the movement areas of an airport, as
|long as they’ve got permission from the tower (Source: used to
|drive a tug at TUL)
|u/hgravesc - 21 hours
|
|I cannot wrap my mind around this
|u/Supergeek13579 - 19 hours
|
|The engines are optimized for high speed, high altitude. During
|taxi they’re exceptionally inefficient.
|u/Open-Oil-144 - 18 hours
|
|Engines have to work a lot more to push the plane forward on
|relatively tiny wheels against the ground, while on the air they
|just need to keep the plane going forward at a constant speed,
|aerodynamics do the rest.
|u/Open-Oil-144 - 18 hours
|
|The same principle sort of applies to ground vehicles too, they
|spend much more fuel going from full stop to accelerating than
|when you're on a highway just pushing it forward at max gear
|leaning on inertia.
|u/PC-12 - 19 hours
|
|>Concorde burnt more fuel taxiing from the gate to the start of
|the runway than a 737 uses to fly from London to Amsterdam.
|Source on that? 738 uses about 3500 lbs/hour down low, plus about
|600 lbs taxi, and then taxi in afterwards. Most 736/7/8 drivers I
|know would use 5,000 lbs hour flight fuel as their minimum rule of
|thumb for shorter/lower flights. The flight is about 1 hour so the
|burn will be somewhere between 3,500 and 5,000 lbs, depending on
|altitude, plus taxi fuel. I think Concorde was 3,000-4,000 lbs
|taxi fuel. I’m skeptical that this is accurate and I’m thinking
|it’s a bit of internet lore.
|u/djdood0o0o - 1 day
|
|A Boeing 747 can typically carry 48,400 to 63,636 gallons of fuel, which
|is equivalent to 183,214 to 240,890 liters or about 180 to 213 tonnes.
|u/Downhilltrajectory - 1 day
|
|The density of the fuel is much lower than water. 180,000 litres would
|weigh around 145 tonnes.
|u/llDrWormll - 22 hours
|
|Quick shoutout to the metric system where 180000L of water equals
|180000 kg. I just think that's neat.
|u/colinstalter - 20 hours
|
|The other day I was doing some head math and thought “how much
|does 1L of water weight again?”. Oh yeah… 1kg. It’s almost like
|H2O was used as the basis for the unit!
|u/QueerBallOfFluff - 17 hours
|
|Tbf, water is also the base for volume measurements in US
|customary units and imperial units, and it's based on weight
|too. In US units 1 gallon is 8 Lb of water. In imperial, 1
|gallon is 10 Lb of water. A US pint is exactly 1 Lb because of
|this, which is pretty neat if you think about it
|u/colinstalter - 16 hours
|
|Except it’s really 8.34 lbs per US gallon. And 7.48052 gallons
|per cubic foot. As an American who likes calculating things in
|my head, I have to do basically everything in metric and then
|switch back at the end.
|u/QueerBallOfFluff - 16 hours
|
|Well that's disappointing, I'm guessing the standardisation
|of the pound did that? I grew up with and work in metric.
|That I know some imperial unit stuff is just a quirk of
|being British
|u/fromYYZtoSEA - 19 hours
|
|I use this multiple times a week when I am preparing a wet brine
|for the meats. 5% brine = put the container on the scale, add 1kg
|(so 1L) of water, and then 50g of salt. Not sure why some people
|find using cups and remembering the conversion easier!
|u/awkwardalvin - 20 hours
|
|Fuel density is typically 6.7-7.2lbs per gallon depending on
|temperature
|u/Potatobender44 - 21 hours
|
|200 tonnes of fuel but yet they try to tell us that a couple people
|sitting in the wrong seat could put the plane out of balance
|u/Ihatedominospizza - 17 hours
|
|Not that I believe it or anything, but if the 200 tonnes of fuel is
|balanced properly, then it’s kind of irrelevant to the rest of
|what’s being balanced
|u/ChonkTonk - 2 hours
|
|If one passenger changes seats, another is going to, and another,
|and another, and suddenly everyone’s going to be fighting over the
|best seats. I work in the industry and we’ve had planes return to
|the gate for this exact reason, because as soon as the average
|American gets on a plane they go feral
|u/setofskills - 21 hours
|
|Reminds me of [this](https://www.reddit.com/r/funny/s/sE7eRRkpjB).
|u/MobbDeeep - 7 hours
|
|So the plane weighs 400 tonnes and has 200 tonnes of fuel onboard. So
|its literally 1/3 fuel? That’s crazy.
|u/relevant__comment - 23 hours
|
|Having a hard time processing the scale. How many football fields is
|that?
|u/Good_Prompt8608 - 22 hours
|
|r/anythingbutmetric
|u/runtheplacered - 18 hours
|
|Do what now?
|u/Good_Prompt8608 - 4 hours
|
|found the american
|u/Awordofinterest - 13 hours
|
|Just 1 football field - The 4litres of fuel would be roughly 0.00075mm
|deep (2.95275591e-5 or 0.0000295275591 Inches). If an American
|football field 120yards (109.728m) x 53.3yards (48.73m) and you poured
|4litres of fuel in to fill the entire area = 0.00075mm depth.
|u/Olde94 - 17 hours
|
|It has 400 seats. So that is 36l per person per hour. I use 5l per hour
|alone in a car on a highway. A 747 moves at 9x the speed i do. From
|what i gather, the problem is not the usage, as it’s lower per person,
|per distance than when i commute to work. The problem is that i can
|travel 8000km in a single day, and will do it, just to get to a beach
|u/ztasifak - 16 hours
|
|I think modern aircraft average about 2.5 litres per seat and 100km.
|The 747 is quite old so it will use much more than that Of course you
|can find cars (maybe hybrids) that use roughly 5 litre for 100km
|having 5 seats. So the car is more efficient (fuel wise, but not time
|wise) in that regard.
|u/Olde94 - 16 hours
|
|A full car wins any day, but let’s be real. Most are half empty. I
|don’t think it makes sense to count a hybrid. The fuel economy is
|always screwed. They tend to list “full battery plus 1L”. For short
|rutes it’s essentially a full electric. For long it’s a gas car with
|slightly worse fuel economy than a non hybrid. So you can’t easily
|use it in a talk about planes
|u/ztasifak - 4 hours
|
|Oh I agree. I don’t have the numbers but probably 90% or more are
|occupied by 1 person
|u/Brave_Dick - 1 day
|
|Just like an F150.
|u/JustCopyingOthers - 22 hours
|
|Would be interesting to see similar stats for a 21st century plane with
|30-40 years of aviation advancement.
|u/MammothDreams - 19 hours
|
|[Enjoy](https://en.wikipedia.org/wiki/Fuel_economy_in_aircraft#Long-
|haul_flights).
|u/JustCopyingOthers - 19 hours
|
|Thanks, I can see why the A380 is dead, about 20% more fuel per seat
|than the most efficient long haul aircraft and that's before any
|empty seats.
|u/DifferentEvent2998 - 20 hours
|
|The engines in the 747 are newer
|u/FapDonkey - 21 hours
|
|Whats more impressive to me is the Top Fuel NHRA Drag Racing cars burn a
|bit more than that (something around 1.5 gallons per second), and make
|something like 20-30% more power in the process (hard numbers are hard
|to find, because they don't make dynamometers big enough to measure
|their output, so its calculated analytically based on strain readings
|taken from the driveshaft). So Imagine 20% MORE power than a 747 needs
|to keep a million pounds of plane/cargo in the air... and it's all being
|used to accelerate your 2,000 pound car up to speed in 3-4 seconds. Drag
|racing is fun.
|u/Caspi7 - 17 hours
|
|Lmao that's a bunch of nonsense. With 4 engines a 747 produces about
|[400.000 hp at cruising
|speed](https://www.calculatorultra.com/en/tool/thrust-to-horsepower-
|calculator.html#gsc.tab=0). All while using less fuel than a dragster
|and producing like a 100 times more power lol.
|u/hypnogoad - 18 hours
|
|Apples to oranges. Jet dragsters are almost as fast as top fuel
|dragster, but use a jet engine that's only around 3000 lbs of thrust.
|A 747 engine has 20 times that.
|u/FapDonkey - 17 hours
|
|LOL what are you even talking about?? The faster jet dragster in the
|world (to my knowledge) is the Fireforce 5, which turn in ET's right
|aroun 5.0 seconds and trap speeds around 300 mph. The current Top
|Fuel record is an ET of 3.6 seconds and a trap speed of 340. A 5.0
|second ET hasn't been competetive in drag racing since the mid 80's
|when Eddie "The Thrill" Hill broke 4.99. If the fastest jet dragster
|in the world is not quite as fast as top fuel cars were 40 years
|ago, I dont think it's really fair to say they are "almost as fast".
|Also, even if all that WAS true... what point are you trying to
|make? Of COURSE its an apples to orangtes comparison. We're talking
|about a commercial jetliner and a (barely) single-seat top tier
|racecar. It's apples to ZEBRAS. I was just putting some interesting
|context around those fuel consumption numbers. There's no argument
|or debate to win here.
|u/Ancient_Persimmon - 17 hours
|
|You're the one who suggested that a dragster has more power than
|an airliner. 10 000ish HP is a lot, but not compared to a 747.
|u/Ihatedominospizza - 17 hours
|
|>there’s no argument or debate to win here Yet you’re trying
|very hard to
|u/Ihatedominospizza - 17 hours
|
|Let’s say that’s true. What’s your explanation on why those cars are
|so slow compared to the plane?
|u/FapDonkey - 16 hours
|
|Theyre not really, or not by much. 747 will cruise at around 500 mph
|depending on conditions. A top fuel car can hit 340 mph. But it does
|that just 3.X seconds from being a dead stop, in less than 1/4 mile.
|So they are going *almost* as fast as a 747 in a VERY short period
|of time/distance. Because that's what they're optimized to do
|(maximize acceleration at expense of all else). the only thing
|stopping them from going as fast as a 747 cruises is the "gearing"
|in the drivetrain, and aerodynamics (for reference, the fast wheel-
|driven land speed car, Turbinator II, can reach 500+ mph, same speed
|as a 747, and a Top Fuel dragster makes 2-3 times as much power).
|u/Drone30389 - 6 hours
|
|Cruise speed is an economy setting. 747s can max out over 600 mph,
|and they're not optimised for top speed either.
|u/Gap-Bowl-Rat - 22 hours
|
|Finally, something that matches Snowrunner's fuel economy
|u/GriffinFlash - 1 day
|
|Good thing I walked to the store and back instead of taking the car.
|u/Knyfe-Wrench - 23 hours
|
|I took the 747
|u/esdaniel - 23 hours
|
|Taylor swift?!
|u/greavesyman - 21 hours
|
|But don't worry, we can offset this by using paper straws
|u/garlopf - 19 hours
|
|This does not make sense. For an 8 hour flight, that equates to more
|than 135 tons of fuel. I guess at takeoff it can peak at that number but
|at cruise it can't possibly be correct.
|u/fuck_ur_portmanteau - 18 hours
|
|Longest ever 747 flight was 20hrs and max fuel capacity is ~213t.
|Which is an average of 3L/s.
|u/John-A - 18 hours
|
|Some models carry 213 tons of fuel or 63,000 gallons. That's enough
|for 17.5 hours, apparently.
|u/swiftpwns - 23 hours
|
|Why is everyone in comments comparint it to cars? Lets do some math
|comparing it to trains!
|u/Laferrari355 - 22 hours
|
|Probably because planes travel twice as fast as the very fastest
|trains, and because trains can’t cross oceans Edit: which now that I
|think about it is also true of cars. But I guess cars are a better
|frame of reference for people
|u/ewest - 15 hours
|
|What about the [Trains Across the Sea](https://open.spotify.com/trac
|k/5menR5pgdVgIiLG2kbCxc9?si=p31N8jddTu242hIc-XE3Ug)?
|u/xXCrazyDaneXx - 23 hours
|
|Trains are... difficult. Yes, if you just compare energy/passenger,
|they are by far the most efficient. But.... That energy has to be
|produced elsewhere, which means that you would have to take the
|environmental effects of an entire energy market and adjust it for the
|percentage used by trains in order to make a somewhat not misleading
|comparison.
|u/swiftpwns - 23 hours
|
|There are environmental effects of acquiring, refining, storing and
|transporting air plane fuel too
|u/xXCrazyDaneXx - 23 hours
|
|Yes, but they're a negative externality of the production of the
|fossil fuel (and would have to be counted into the production of
|the electricity for the trains as well), and not a direct
|consequence of the passenger transport in itself.
|u/Ihatedominospizza - 17 hours
|
|Forgot that there are trains running on electricity lmao
|u/Thotaz - 22 hours
|
|What? Are you suggesting we wouldn't be building out a power grid
|and have power plants without trains? Looking at the train energy
|consumption by itself seems perfectly reasonable in my eyes.
|u/xXCrazyDaneXx - 22 hours
|
|I am suggesting that just looking at the energy consumption of a
|train *ceteris paribus* would give misleading results about the
|*actual* emissions from train travel as 60% of the world's
|electricity is produced using fossil fuels [IEA,
|2023](https://www.iea.org/energy-system/electricity)
|u/Wolfpacker76 - 1 day
|
|Where do they store all of that fuel? In the seats??
|u/30625 - 1 day
|
|In the fuel tanks in the wings, the body and the horizontal
|stabilizer. 747-400 consumes roughly 10tons/hour. So it is a little
|less than 3,5liters/second as an average value.
|u/TheLizardKing89 - 1 day
|
|Most planes have fuel tanks in the wings.
|u/Wolfpacker76 - 1 day
|
|I know that, and in the body. But 1 gallon a second on a 10 hour
|flight? That 36,000 gallons of fuel. Edit: 747 holds up to 56,000
|gallons of fuel, that’s insane.
|u/airpipeline - 19 hours
|
|One gallon of aviation fuel weighs 6.7 lbs, 86% of that is carbon, 5.76
|lbs. Every second a 747 leaves behind the equivalent of about a 5 lb
|bag of charcoal briquettes. But in reality, the carbon is combined
|with oxygen and one gallon of jet fuel is turned into 21.15 lbs of CO2.
|337,319.2 lbs of CO2 from LAX to NYC.
|u/fuck_ur_portmanteau - 18 hours
|
|Sustainable Aviation Fuel is the only viable method to reduce
|emissions in the near future and it’s already being implemented. It
|can reduce lifecycle emissions by 80%. The cost, production capacity
|and sourcing feedstock are the biggest barriers to widespread use,
|but it’s technically perfectly possible and is expanding rapidly.
|u/airpipeline - 11 hours
|
|You’re of course right, it’s a hard problem! I’m not saying it
|is easy, especially as we lately seem to favor systematically
|dismissing science, but it is a problem nonetheless. i
|suppose that we lessen our dependence on burning carbon, we
|start building sea walls or both. We cannot even invent
|technology to limit the affects of climate change, because it
|isn’t real, according to some (like the big oil companies and
|the recipients of their political contributions). Wasn’t
|Ethanol created as a political favor to farmers in Iowa, the
|first state to hold presidential primaries? Not that it would
|make a good jet fuel but I thought that at least the farmers
|like it. No?
|u/John-A - 19 hours
|
|That might only be at takeoff and the climb to cruising altitude. That's
|the only time they normally use close to full throttle, with them
|dialing it back to something like 25% at altitude. Plus, the reality of
|thinner air means the engines are using considerably less fuel than that
|once up there as well. Then again that's a very big plane and might
|well carry enough fuel for a gallon a second for a 16 hour flight after
|all.
|u/SurveyNo5401 - 16 hours
|
|For a 4 hour flight: 60 seconds x 60 minutes x 4 hours = 14,400
|gallons? That sounds like way too much, thinking about the volume and
|weight of it. Can someone tell me why I’m wrong
|u/Seraph062 - 15 hours
|
|Max fuel load on the 747 is something like 50-60,000 US gallons, and
|the longest 747 flight I'm aware if is about 16 hours. So if
|60,000 gallons gives 16 hours then 14,400 gallons for 4 hours seems
|very reasonable.
|u/K3TtLek0Rn - 15 hours
|
|Every time I hear this I just can’t believe the thing can hold enough
|fuel for hours long flights
|u/jellenberg - 11 hours
|
|It's kinda impressive. If I remember right, the 747 can hold around
|60,000 gallons of fuel. They put fuel everywhere they can, even in the
|tail.
|u/Mondilesh - 11 hours
|
|I'm more interested in how all that fuel gets to airports for refueling.
|Seems like way too high a volume to truck it in, so it's like a jet fuel
|pipeline direct from a refinery? 7
|u/WeirdTalentStack - 10 hours
|
|Correct, sort of. Refinery to airport tank farm for the most part.
|u/jocax188723 - 5 hours
|
|For comparison: Generic car: at 30 MPG/60MPH, that's 0.000769
|gallons per second. Generic bus: approx. 6MPG average, so 0.1
|gallons per second. 747: 1 gallon per second per engine at cruise,
|so 4 gallons per second. Modern Airbus A350: about 1165 gallons per
|hour of cruise, so 0.324 gallons per second. Saturn V 1st stage: About
|20 tonnes per second of kerosene and oxidizer, or approx 5700-ish
|gallons per second.
|u/Krocsyldiphithic - 4 hours
|
|That's honestly a lot less than I thought
|u/lardoni - 21 hours
|
|About on par with your average American car isn’t it?
|u/sparkywilly - 22 hours
|
|But their fuel capacity is only 64,225 max meaning they can only fly for
|4.5 hours. Something's not adding up....
|u/davguy95 - 21 hours
|
|64,225 gallons or 243,118 liters, if it uses 1 gallon per second then
|it burns 3600 gallons an hour (60x60=3600) meaning it has 18 hours of
|flight time to use 64800 gallons. I think you may have gotten the
|gallons and liters confused.
|u/sparkywilly - 13 hours
|
|I just got math confused and did know wtf I was talking about.
|Source: am regarded.
|u/SomethingAboutUsers - 21 hours
|
|You suck at math, that's what's not adding up. 64,225 gallons of
|fuel/3600 gallons per hour= 17.84 hours The reality will be somewhat
|less, because there are reserves they can't/won't go into and not all
|altitudes have the same fuel consumption, so call it 12-14 hours of
|flight time with lots left over.
|u/sparkywilly - 13 hours
|
|Well I was adding the way Terrance Howard does.... So you may be
|right about my math....
|u/Old_Week - 21 hours
|
|Taking off takes a lot more fuel than cruising
|u/Kind-Sherbert4103 - 20 hours
|
|About the same as a top fuel dragster burning nitromethane.
|u/Repulsive-Lobster750 - 19 hours
|
|But it also carries you mom
|u/Pleasant_Ad_7694 - 19 hours
|
|Why in my head do I feel like for a full flight it'd be airplane loads
|of fuel. I can't imagine this quantity usage over time. How many liters
|do they carry?
|u/Adventurous-Depth984 - 18 hours
|
|A single round trip transatlantic flight uses more fuel than an average
|person will use in their entire lifetime.
|u/teemu_8812 - 18 hours
|
|So with that math, flying 300 people to Spain from Lapland would be more
|cost effective and more ecological than driving them all to there. We
|should be all flying jumbo jets to work!! :D
|u/SaveTheSterling - 18 hours
|
|And governments subsidise this in the tail end of a climate disaster.
|Bleak.
|u/FaendalFucker69 - 17 hours
|
|Once took a heli tour and asked the pilot how much fuel it burns through
|and he said a gallon per minute. In this context, it makes sense.
|u/Remarkable-Piece-131 - 17 hours
|
|A d is pumping all that exhaust into the upper atmosphere.
|u/buckzor122 - 17 hours
|
|Yeah, and I commonly find £20 flights in Europe. How the fuck do
|airlines make money.
|u/Seik64 - 16 hours
|
|not using a 747 for short flights is a good starting point.
|u/darybrain - 17 hours
|
|How does it compare to other modes of transport carrying that many
|people over that full range? Which is more efficient?
|u/ztasifak - 16 hours
|
|Probably a few litres per 100km per passenger Modern aircraft use
|about 2.5 litre per seat per 100km. The 747 is quite old. Probably
|double that value or more
|u/Ok-Yoghurt9472 - 16 hours
|
|it's because they have to do chemtrails /s
|u/notasthenameimplies - 15 hours
|
|To add to this,at take off each engine uses more than 1gallon persecond.
|u/Ryan1869 - 13 hours
|
|Always interesting that airplanes report fuel efficiency in gallons per
|hour instead of miles per gallon.
|u/jellenberg - 11 hours
|
|Because this takes wind out of the equation. Those Jetstream winds
|would really skew the numbers otherwise.
|u/Kettle_Whistle_ - 12 hours
|
|747 stayin’ hydrated It’s how it lifts so well at its age. No
|steroids.
|u/SurealGod - 11 hours
|
|With the size of those engines, I would've reckoned that they consume
|more than that
|u/matrixsuperstah - 11 hours
|
|Nothing but flying swimming pools.
|u/dav_oid - 9 hours
|
|At 570 mph cruising speed that's 9.5 miles per minute, or: 570 Miles Per
|Gallon. That's at least 400 people, or: 1.4 MPG per person.
|u/Forever-Lurking - 9 hours
|
|You’re off by a factor of 60. There are actually 3600 seconds in an
|hour. The 747 gets about .16 MPG
|u/DirtySouthDoc - 8 hours
|
|I as an American appreciate you using the gallon as a measurement.
|However I’m still confused. How many Bald Eagles to a gallon?
|u/last-resort-4-a-gf - 7 hours
|
|Can't wrap my head around how much fuel it can hold for a 10 hour flight
|u/Synthetic-Cellophane - 6 hours
|
|I guess my car actually gets good milage. I’ll stop complaining.
|u/JardinSurLeToit - 5 hours
|
|And looks good doing it.
|u/kushbom - 58 minutes
|
|Flying fuel tank ?
|u/Mhisg - 21 hours
|
|But don’t worry your 15mpg car is the problem.
|u/acdgf - 20 hours
|
|A 15mpg car will burn as much as 5 times as much fuel per passenger
|mile as a 747. The 747 has also been all but discontinued for pax
|transport, and replaced with more efficient planes.
|u/Aurora428 - 19 hours
|
|I mean the average car has 1.5 people in it and you're comparing it to
|a plane that seats 366 people Planes are more efficient than cars and
|that's ignoring the fact that your car isn't a suitable alternative to
|air travel.
|u/chromaaadon - 20 hours
|
|As someone who has done multiple 15 hour flights. I find it staggering
|that they basically red line the engines for 15 hours, refuel and do it
|all again for thousands of hours. And how the fuck do they store enough
|fuel to do so???
|u/nails_for_breakfast - 20 hours
|
|They don't redline the engines at all outside of emergency situations.
|The only time they come close is during the beginning stages of
|takeoff. And jet engines are fundamentally different than the
|reciprocating engines in most cars/trucks in that staying at one speed
|for a long time is not very mechanically taxing one them.
|u/Aggressive_Let2085 - 14 hours
|
|The wing tanks in the largest airliners are big enough to basically
|stand in. The size of these fuel tanks are incredible.
|u/dr_reverend - 20 hours
|
|Not all that impressive. A top fuel dragster uses about 20 litres of
|fuel per second.
|u/Electricpants - 20 hours
|
|Are those running all day everyday across the world?
|u/dr_reverend - 15 hours
|
|What does that have to do with anything? I thought we were playing
|the “numbers go up” game.
|u/Adventurous_Top_9919 - 21 hours
|
|My understanding is that this is at take off. Marinating fuel costs are
|a fraction of that, especially when they are in the Atlantic lanes at
|high altitudes.
|u/taco_eatin_mf - 21 hours
|
|Fuck!!!
|u/the_cardfather - 20 hours
|
|This blows my mind because a cross US flight like the ones that were
|hijacked in 9/11 is about 4 hours or 15k gallons of fuel. Apparently
|they hold 4-5x that much. 🤯
|u/Benutzernarne - 16 hours
|
|Flying is horrible for the environment
|u/jellenberg - 11 hours
|
|Because driving is better?
|u/Cynfreh - 23 hours
|
|Shocking planes cause shit loads of pollution but no one cares for some
|reason.
|u/Laferrari355 - 22 hours
|
|Because per passenger they’re still more efficient than cars. They
|also are the only practical way to cross oceans, or to travel long
|distances. They’re also much safer than cars. They have their
|disadvantages, pollution being one of them, but generally they’re a
|net benefit to society
|u/Platforumer - 21 hours
|
|They are not more efficient by much. Planes also emit high in the
|atmosphere which amplifies the greenhouse gas effect. Also if you
|compare to electric cars, planes generate much higher emissions.
|u/Cynfreh - 22 hours
|
|How many people would drive instead of flying though it's not really
|comparable most flights are just for pleasure anyway, to me flying
|is one the things we should be trying to dial back on to reduce
|overall pollution.
|u/DinkleBottoms - 21 hours
|
|Most travel is for pleasure. Cutting flying increases travel time
|by hours up to days. A 3.5 hour flight from San Francisco to
|Dallas is a 2-3 day car ride and taking the train out of Los
|Angeles is a day and a half long journey.
|u/damnalexisonreddit - 20 hours
|
|Is that why they keep going down?
|u/Aggressive_Let2085 - 14 hours
|
|It’s been quite some time since a Boeing 747 “went down” 2017 was the
|last time one had a full hull loss. If you’re trying to make a joke
|about Boeing, it’s been over 5 years since the MAX accidents where
|planes went down, and that issue was fixed. So id like it if you can
|let me know what airliners are going down? Especially since the USA
|hasn’t had one go down in over 10 years, and that was due to pilot
|fatigue.
|u/matt82swe - 1 day
|
|Can I get the time metric in freedom (MAGA?) units?
|u/michal_hanu_la - 1 day
|
|A second is approximately 0.8 microfortnights.
|u/Bowens1993 - 1 day
|
|About 14 Coors Light cans in as long as it takes for someone to shout,
|**"Let’s go, Brandon!".**
|u/CJVCarr - 1 day
|
|That's ~ 1 gallon of fuel in around 1150ft of projectile distance from
|the muzzle of a Glock 19.
|u/XenonTheMedic - 21 hours
|
|3 gallons in the time it takes a bald eagle to cry
|