Energy efficency: car vs. bicycle vs. bus

A poor, knee-jerk point in several ways. You (presumably) don’t know that the OP doesn’t have a bicycle. He may well have.

You do know that he’s got an old car that he doesn’t use very much. Do you really think the environment is going to benefit by him scrapping it (with the waste and pollution that implies) and buying a (presumably new) hybrid (with the energy and materials cost and pollution that that implies) and then not using it very much?[/quote]

So Mr poor knee-jerk point of view… what do u drive? what is your contribution to the environment? do you even know what kind of hybrid am i talking about? it may as well be a car-boat hybrid… or a car-plane hybrid… or an electric or gas bicycle…

A poor, knee-jerk point in several ways. You (presumably) don’t know that the OP doesn’t have a bicycle. He may well have.

You do know that he’s got an old car that he doesn’t use very much. Do you really think the environment is going to benefit by him scrapping it (with the waste and pollution that implies) and buying a (presumably new) hybrid (with the energy and materials cost and pollution that that implies) and then not using it very much?[/quote]

So Mr poor knee-jerk point of view… what do u drive? what is your contribution to the environment? do you even know what kind of hybrid am i talking about? it may as well be a car-boat hybrid… or a car-plane hybrid… or an electric or gas bicycle…[/quote]

Jeez! Someone else lining up to take an irrelevant pop at my car? Take a number and wait your turn.

Since you ask, my contribution to the environment is mostly piss, shit and curmudgeonly critical thinking.

Not great, but could be worse (see above).

Which is what, exactly? :unamused: I have a car that works, and works well. You say I should change it. Why? By the way, I have a bicycle, but its a pain in the arse pedaling it to Taizhong and back with the wife and kid on the back. :unamused:

A poor, knee-jerk point in several ways. You (presumably) don’t know that the OP doesn’t have a bicycle. He may well have.

You do know that he’s got an old car that he doesn’t use very much. Do you really think the environment is going to benefit by him scrapping it (with the waste and pollution that implies) and buying a (presumably new) hybrid (with the energy and materials cost and pollution that that implies) and then not using it very much?[/quote]

Quite so. I will also add that through several U.S. studies into carbon dioxide production through oil burning, and due to oil consumption levels associated with the agro-industry, it has been proven far more efficient to drive a car with two people in it as opposed to riding two bicycles. Cars are enormously more efficient than any road going transport when they are full, even more so than walking.

The black and white days of environmentalism are far behind us. We should be thinking a little more for ourselves it seems.

[quote=“sulavaca”]
it has been proven far more efficient to drive a car with two people in it as opposed to riding two bicycles. Cars are enormously more efficient than any road going transport when they are full, even more so than walking.

The black and white days of environmentalism are far behind us. We should be thinking a little more for ourselves it seems.[/quote]

if that is the story that lets you sleep every day then let it be…

dont get me wrong, i aint walking or riding a bicyle… i wont say what i drive because someone may call the police on me to see if my air pressure is right or if my engine is modified or if i had a beer or 2… hey who knows…
and the best part is that i like what i drive and i enjoy it… but i know it is not the best for the environment as any other car around and i know walking would be better…
btw, a cow produces more CO2 during a year in farts than a car… and we eat them every day !!

[quote=“omerojs”]if that is the story that lets you sleep every day then let it be…
…btw, a cow produces more CO2 during a year in farts than a car… and we eat them every day !![/quote]

I don’t understand your reaction.

[quote=“sulavaca”][quote=“omerojs”]if that is the story that lets you sleep every day then let it be…
…btw, a cow produces more CO2 during a year in farts than a car… and we eat them every day !![/quote]

I don’t understand your reaction.[/quote]

Even if you did, it’d probably just depress you.

Incidentally, at the (slight) risk of opening a “second front”:-

is a bit hard to believe. I (admittedly only vaguely) remember a comparative Scientific American article a long time ago and the only thing more efficient than a 747 was a man on a bicycle.

How about a full Routemaster double-decker bus with one of the modern diesel retrofits?

I thought the same until I started following this up. The figures are out there to work out for yourself.

dieoff.org/page40.htm

I thought the same until I started following this up. The figures are out there to work out for yourself.

dieoff.org/page40.htm[/quote]

If there are figures on there sufficiently detailed to allow me to make that calculation, I didn’t spot them.

The relevant figure I did see, however, allows some crude guesstimates.

They say it takes 400 gallons of oil to feed an American for a year.(As so often, Americans are very much a worst case here)

That’s 1.095890411 gallons/day, but they’ll presumably only be those little toy US gallons, so not quite as bad as it at first seems.

According to this sitehttp://www.cptips.com/calex.htm#enoth, Cycling at 20mph uses 37Cal/mile, Thats 17760
Cal for 480 miles if you cycled for 24hrs

According to the UN FAO, the average American consumes 3770 calories (That should be kcal or Cal, tut tut) a day.

http://www.fao.org/statistics/yearbook/vol_1_2/pdf/United-States-of-America.pdf

So cycling for 24 hrs at 20mph increases your calorie consumption by 4.71
fold (much more than I would have guessed, though its an over-estimate because the FAO figure will include some Americans who take exercise, and even some American cyclists, though not many doing 480 miles a day) equivalent to 5.16 US gallons, on which you travel 480 miles, or

92.98 miles / US gallon

But thats per person, so against two people in a car its equivalent to about 47 miles/US gallon. Still better than most cars, but not by much. Damn!

(Edit: Or I’m wrong, of course.)

The cycling edge will presumably be greater for people on non-American high carb/low meat diets.

This calculation also ignores the difference in energy value between “oil” and refined vehicle fuel, which will tend to favor the car in the comparison.

I can’t think about the Routemaster today, I might think about that tomorrow.

Edit: Not much thought apparently required really.

Routemaster RML has/had 72 seats, and officially 5 standing (almost sure I remember more in practice) and is variously reported to do 10-13 mpg, probably depending on the engine fit. Those’ll be British, Imperial gallons, so the lower figure = 8.326 US mpg, which works out at 641.10 person-mpg

Volkswagen Jetta (I dunno any American-made diesel cars. There’ll be an “economy” option on some huge pickups for cowboys of a pinko brokeback-mountain persuasion, doubtless, but thats not a very fair comparison) is quoted at 30mpg city (probably fair comparison with the bus), or 150person-mpg if its carrying 5 people.

IOW less than a fourth of the efficiency of the bus. Seems a no-brainer, unless I’ve screwed up.

Sorry Mr S. Its STILL a bit hard to believe.

There are a lot of cars which are more efficient than two cyclists but I should have said that in practice cars are the most fuel efficient transport in general. This is due to buses and trains rarely running at anywhere near full capacity. The results of these studies are not new.

Trimming the Privett a bit, Mr S.

Well a lot, actually.

On my (admittedly imperfect, but tending to worst-case for the cyclist) calculation above there are going to be rather few cars more efficient than two cyclists, though it came out a lot closer than I’d expected. If you have better figures or sources (which may well exist for all I know) this (or earlier) would have been an appropriate time to reveal them, though I suppose I should have done some searching myself rather than working my fingers to the bone wiv sums, .

Wikipedia has 670mpg for the cyclist, which is WAY better than my figure. No car outside weird record breaking specials is going to remotely challenge that, but they are probably only accounting for the direct energy expenditure in petrol-equivalents, and not accounting for the energy cost to produce the food, which I attempted. OTOH I didn’t attempt to factor in the energy cost to produce the vehicle fuel, which would make the car do relatively worse.

Your second hedge, as well as hurling the goal posts way off the pitch, implies that you think its fair to compare a full car with a 3/4 empty bus. For all I know buses often run 3/4 empty, seems quite likely, but OTOH cars very seldom run full.

Trimming the Privett a bit, Mr S.

Well a lot, actually.

On my (admittedly imperfect, but tending to worst-case for the cyclist) calculation above there are going to be rather few cars more efficient than two cyclists, though it came out a lot closer than I’d expected. If you have better figures or sources (which may well exist for all I know) this (or earlier) would have been an appropriate time to reveal them, though I suppose I should have done some searching myself rather than working my fingers to the bone wiv sums, .

Wikipedia has 670mpg for the cyclist, which is WAY better than my figure. No car outside weird record breaking specials is going to remotely challenge that, but they are probably only accounting for the direct energy expenditure in petrol-equivalents, and not accounting for the energy cost to produce the food, which I attempted. OTOH I didn’t attempt to factor in the energy cost to produce the vehicle fuel, which would make the car do relatively worse.

Your second hedge, as well as hurling the goal posts way off the pitch, implies that you think its fair to compare a full car with a 3/4 empty bus. For all I know buses often run 3/4 empty, seems quite likely, but OTOH cars very seldom run full.[/quote]

Wikipedia is wrong when it comes to the cyclist.
I’ve put together figures from many different sources in the past and to be perfectly honest, I can’t be bothered to put them together again now, unless someone wants to pay me to do it. It’s been quite some time since I did it last and I don’t believe the public are willing to believe them anyway. Please don’t take it personally.

Also a quote from Wiki

I am not comparing a full car, I believe I mentioned one with two occupants.
A car carrying two people is saving two people from working as engines on bicycles. The other added benefit is its potentially saving one extra road trip made by an internal combustion engine.

Here are plenty of cars which are extremely fuel efficient.
You take any of those cars and you put in one more occupant.

Mr S said cars were more efficient than two bicycles, and you could work it out for yourself, so I did, and AFAICT, they aren’t.

He also said “Cars are enormously more efficient than any road going transport when they are full,” which’ll probably be true if the car is full and the other road transport isn’t (and maybe also true at average occupancies of cars and public transport, though that isn’t what he said).

The latter point is in any case no basis for personal decisions on transport use, since the public transport is running anyway. So yes, irrelevant twaddle, and I apologise for my part in it.

But before I get me coat, 4WIW I think Mr S. and I are agreed that, relative to a new car, the environmental benefits of running an old car are clear and undeniable.

Mr S said cars were more efficient than two bicycles, and you could work it out for yourself, so I did, and AFAICT, they aren’t.

He also said “Cars are enormously more efficient than any road going transport when they are full,” which’ll probably be true if the car is full and the other road transport isn’t (and maybe also true at average occupancies of cars and public transport, though that isn’t what he said). [/quote]

I actually said: [quote]Quite so. I will also add that through several U.S. studies into carbon dioxide production through oil burning, and due to oil consumption levels associated with the agro-industry, it has been proven far more efficient to drive a car with two people in it as opposed to riding two bicycles. Cars are enormously more efficient than any road going transport when they are full, even more so than walking.[/quote]

I’m sorry I can’t spend the time to go through the calculations for you. I am quite busy of late. If I find time in the future, I will be happy to go through them once more for you.
It was recently shown in many countries that due to average capacity cars were in fact more efficient on a reality basis than other forms of road transportation. It isn’t the same as saying that with the correct implementation that public transport couldn’t compete.

Wikipedia quotes The US Transportation Energy Data Book (2006) which gives the following occupancy rates and energy consumptions (in MJ/passenger km) for different transport forms

Vanpool 6.1/0.867
efficient hybrid 1.57/1.088 (that “efficient” sounds like a self-fulfilling selection)
motorcycle 1.2/1.216
rail 20.5/1.737
car 1.57/2.302
bus 8.8/2.776

So, in the US in 2006, non-hybrid cars were better than buses but worse than several other forms of transport. The US is however an especially challenging environment for public transport due to cheap petrol and high car ownership.

Its also probably true that these will be relatively inefficient buses. I chose the AEC Routemaster mostly out of ex-Londoner nostalgia, though I had the impression that it was relatively light. Turns out that, although its a 1954 design, its much lighter and about twice as fuel-efficient as a modern bus, largely because its an aluminium monocoque structure. There was of course a lot of recent experience (and capacity) for building these in the 50’s, due to recent mass-production of Lancaster etc. bombers.

If you look at the way things work in third or second -world places like Thailand (Songthaew’s - usually Toyota pickups with extended seating) North Africa (serveece taxis - usually big old Mercs or Peugeot saloons) or West Africa (Mammy Waggons - traditionally Bedford lorries) its evident that public transport can be very efficient.

Of course less car competition, lax or no regulation, and low operator wages all help, but I wonder if the “don’t leave until full” operating principle which ensures high utilisation could be applied in the west?

Don’t remember hearing of it being tried, but that “Vanpool” referred to above, which comes out tops in the comparison, might be something similar.

I’m sorry but this is some of the most self-serving idiocy I have read in a long time. Forgotten in the equation is that people have to consume calories no matter what and the average diet give plenty of extra fuel for cycling or walking. One simply has to look at a country like China to see that as cycling and walking has gone down, CO2 and pollution levels in all cities have risen (to say nothing of the additional pollution caused by producing the cars in the first place). Yet according to you guys it should have been the opposite. As car used increased and bike use decreased we should have seen CO2 levels drop. Perhaps not at the city level but overall. That has not happened and of course could not happen.

You see, what you are doing when you add cars is increasing on the base load of energy consumed. There is no neutral situation where humans do not eat so it is disingenuous to pretend otherwise.

Less of the “you guys” Mr Man. I said I found the car-better-than-bicycle story hard to believe, and 4WIW my sums don’t support it, though its closer then I expected, and its quite possible my sums are bollocks.

Edit:What you are doing, OTOH, is simply making an unsupported counter-assertion to Mr S’s unsupported assertion.

You are assuming that bicycling doesn’t increase calorific intake, and is, in that sense, free energy. For casual recreational low-intensity cycling by an overfed American this might be true, (unless it makes him/her “hungry”) but its very much the “best case” for cycling and a poor counter-argument.

[quote=“Ducked”]Less of the “you guys” Mr Man. I said I found the car-better-than-bicycle story hard to believe, and 4WIW my sums don’t support it, though its closer then I expected, and its quite possible my sums are bollocks.

Edit:What you are doing, OTOH, is simply making an unsupported counter-assertion to Mr S’s unsupported assertion.

You are assuming that bicycling doesn’t increase calorific intake, and is, in that sense, free energy. For casual recreational low-intensity cycling by an overfed American this might be true, (unless it makes him/her “hungry”) but its very much the “best case” for cycling and a poor counter-argument.[/quote]

Sorry didn’t mean to include you. But I am hardly making an unsupported counter-assertion. It is simply a fact that the way our societies currently work people consume far more calories than they need which yes means that the calories we need to bike and walk are not going to add to the amount of fuel used to grow and transport food to supply those extra calories. Because those extra calories already exist.

If sulavaca is correct then everyone driving a scooter to do all their daily chores (bank, 7-11, supermarket) would consume less energy overall than walking or riding a bike. That’s absurd and one hardly needs to argue with figures to make that assertion. Walking and riding a bike do consume free energy in the sense that that energy already exists (we have to eat) as say the wind to supply wind power or water to generate hydro power already exists. No one would say that a gas plant is more efficient than a hydro plant because it takes less energy to bring the gas to the plant than water to the reservoir (because rainfall does the work for free). But that is exactly what this argument sounds like to me.

calculations of energy used should include the energy used by the driver and the passengers in basal metabolism and in load-activated metabolic increases while driving. Fair’s fair: if you refuse to do that, then when you count the bike, the bike itself is all that can be counted, and a bike uses no energy while it is being ridden.

I think its reasonable to neglect any metabolic increases due to driving, since its a reasonable assumption that they will be rather small. Basal metabolism applies to both vehicles, so can be ignored.

I think its probably not reasonable to entirely neglect metabolic increases due to cycling on the assumption that they will come from the existing, unmodified diet, though this may sometimes be true.

I assumed all the metabolic increases due to cycling would result in an increase in calorific intake. This is (sort of) a worst case assumption for cycling. I also took fairly energetic cycling (20mph) for comparison. Efficiency would be greater at lower speeds, but even so, cycling seems to come out ahead of most cars.

There would be other energy inputs in a full accounting (tyres, lubrication oil and energy for construction) over the life of the vehicle, and these would probably tend to favor the bicycle too.