cerewa

https://www.canadiandriver.com/articles/gw/vw1litre.htm

Summary: VW builds a car that can get about 300 miles per gallon. It seats two and weighs 600-something pounds and uses carbon fiber, magnesium, titanium, etc to achieve that ultra-light weight, and would probably cost $30,000 US with economy-of-scale production.

Not to rain on their parade, but my bike is made of cheap low-tech materials, gets about 300 miles per gallon (actually I'm just guessing on that one), carries two people with the addition of some BMX pegs, and weighs about 30 pounds. The price for a comparable bike at a bike shop? $180 or so.

Well, it's not a really fair comparison, since the VW protects its occupants from the weather, and can probably go 70mph+.

In some ways a fairer comparison is a velomobile with lots of batteries and a nice big electric motor. Which would weigh about 150 pounds, uses cheap materials, and costs only a few thousand dollars.

Somehow I'm just not impressed with the idea that a two-passenger vehicle is "lightweight" at 600lbs. They've got a long way to go before they have something that seems lightweight (for a fast, enclosed 2-passenger machine, even) to cyclists and velomobilists.

gosmsgo

That just goes to prove that we can make small cars that get great gas mileage. The reason why even the smallest cars in the US weigh 3500 pounds is because everyone is afraid of getting hit by an suv in a 400 pound car.

tfahrner

the issue is speed and safety at speed. safety at high speeds (faster than humans typically travelled before 100 years ago, 20 MPH or so) is really expensive in energy and money, and will only become moreso i think, no matter what. i prefer to conceive of a low-speed future, not as a concession to hardship but as an improvement, a liberation from the industrialization of human mobility. as gandhi said, "there is more to life than increasing its speed."

acroy

FYI SMART cars are here.
It says Q1 2008 but i saw one in Dentons, Teaxas, of all places, on Wednesday.
https://www.smartusa.com/index.aspx
now there's a very cool little city car.

wahoonc

Neat car...but no A/C and no cupholders It is a modern retake of the old cycle cars that were built in Britain in the 30's. There was a US built car of similar design that utilized at big Briggs and Stratton motor back in the late 70's, with mileage in the mid 60's range. Interesting how form follows function and it looks a lot like the Honda Insight. Maybe we need to ban all vehicles weighing over a certain amount to certain lanes of the high ways and allow smaller lighter vehicles to have their own lanes, similar to the commuter lanes around some of the major cities, then we wouldn't have to worry as much about getting squashed by over sized SUV's. I also think in the US's case, better driver training and licensing vehicles by the pound would go a long ways towards improving the situation...

Aaron

jonathan180iq

I'd say you do much better than 300mpg.
Last year, I averaged 715 mpg, using a straight calorie-per-mile-burned equation.

lyeinyoureye

Yeah... They figured the price wasn't worth production. Apparently, they've talked w/ suppliers and brought it down, although I dunno how much. Given the drop in the dollar it'll likely still be $30k US even if they can make it for $15k Euro by 2010.
Probably closer to ~100-200mpg fossil fuel equivalent depending on your diet, and less w/ someone else. If ya wanna get all pro-bike about it, ya could even go as far as finding a downhill, and calculate the proportion of yer basal metabolism needed to get on the bike and keep yerself alive while coasting down the hill for really high mpg figures. A longboard can probably be made for a few bucks, can carry two, and is just as efficient mas o menos. But... It's not nearly as comfortable and quick as a bicycle, just like the bicycle isn't as comfortable or quick as a small car. Pay more to get more, but the more ya pay the less ya get.
There ain't no such beasty. Believe me, I've checked. Generally, it'll be fairly efficient no matter what, but it'll either be a few grand and slow, or $10k+ and fast...er, than the slow one. Range will also be less, but the nice thing about that is the user can build however much range they want into it. It'll also be relatively spartan.
They had to go overboard with safety since most people don't think small cars are safe as well as the usual bells and whistles IIRC.

yes

Lye,
I'm guessing that your estimate of bike mpg assumes that the biker eats more to provide the calories, but the exercise doesn't affect their weight. To be truly meticulous, you should start including the extra basal metabolism due to obesity of the car driver. Take the average weight of cyclist and non-cyclists. Get some basal metabolism per unit kg values for humans, and go to town. Then you have to account for the additional calories required to haul the lard carcasses around. Basal metabolism takes care of living, but not moving. The drivers may have an extra 15-30 pounds from lack of exercise need to be moved up and down stairs.
Alternatively, you could count the bike riding as both exercise and transport. Then, you could compare it to the driver driving around, then driving to the gym, getting exercise, and of course, you have to account for building the gym and powering the lights.
Just counting calories burned and ignoring the health and environmental benefits of the exercise is no better than ignoring the calories altogether.

lyeinyoureye

Now way no how. Energy storage is energy storage. Just because I filled up my car a month ago doesn't mean the fuel I'm using right now doesn't count, just like eating excessively at some earlier point in time doesn't mean it's not counted when cycling. People store energy for use via fat, and a car's source of energy is liquid fuel. Now, I'm not saying that cycling doesn't have any other benefits, just anything it has plenty of pros and cons, but, I'm talking about energy efficiency alone in this thread wrt to cycling, not much else.

yes

Lye, here is another way of looking at it. If a person overeats, then some small amount of activity does not require him/her to eat more. If we confine the conversation to America for a moment where 2/3 are obese, then biking may require no additional fuel.
Sure, you can calculate some miles per 'gallon' if you assume that additional fuel is actually needed to bike. However, a typical American person would not need to eat any additional calories to ride a bike say 10 miles per day. They already eat plenty for other reasons. Some calories are needed to live, but looking at the marginal (an additional cookie or muffin) effect of eating, calories are an unwanted side-effect of food. Hence the large market for olestra, diet junk, etc.
If your car consumed $100 per week in gas regardless of how far you drove, then you mpg would not be too meaningful.
If we think of it in terms of energy storage, you could say that energy storage is not free for a human. If they want to store an extra 20 lbs, then they have to expend lots of energy to do so. It increases the surface area (increasing heat loss), which increases the basal metabolism. It also requires more energy to lug that extra weight around. This issue certainly isn't trivial. If someone is 20 lbs overweight, they would require an additional 125 kcals /day just to breath. That is equal to about 3 miles on a bike. If they actually have to walk around a bit during the day, that would be even more calories. So, if a bike commuter loses weight, then they can calculate an calorie savings associated with that.

lyeinyoureye

It may not require them to eat more, but by overeating in the first place, they are building up however much energy, at the rate of ~3500Cal/lb of fat, to possibly use at some later point in time. What you're saying could apply to just about anything, such as chopping wood, hand washing laundry, building a house, etc... However, it doesn't make cycling free from energy wrt a comparison with other forms of transportation. America's weight problem is America's weight problem. People can deal with it by eating less in order to return to a healthy weight, or walking more, or running, or biking, or chopping wood, or some combination of stuff. But, that doesn't mean those calories they're using on a bike, with all the fossil fuels needed to get them to the consumer, shouldn't be counted.

yes

Whether or not food 'should be' counted is up for debate. It essentially changes the meaning of the result. In life-cycle studies the difference is an attributional versus an average approach. You are advocating the average approach in this case, and I am advocating the attributional or marginal.

If you just want to compare the efficiency of the machinery, that is fine, but you should either fuel the human with something efficient (say a combination of rice or pasta and nitrogen fixing legumes), or, you could try fueling the car with some equally inefficient chemical, say by adding some viagra (or other fine chemical) to the fuel.

I'm pointing out two things: (1) being fat costs energy. You can store a lb of fat by eating 3500 Calories. However, if you want to keep it, you are going to have to spend additional energy to keep it stored.
That is how fat people can continuously over-eat without growing exponentially. (2) As a practical matter, 2/3 of Americans are obese. We could use less fossil fuel by eating less, but that is not going to happen. As such, exercise is not causing this portion of the population to eat any additional calories. In fact, it would allow them to eat less!

lyeinyoureye

Not according to what I'm talking about, which is the fossil fuel equivalent efficiency of different forms of transportation. If someone grows all their own food w/ no, or very few, fossil fuel inputs, they have a fairly high, or incomparable, fossil fuel equivalent efficiency rating. If they have a diet composed of products from industrial agriculture, their fossil fuel equivalent efficiency is ~100-200mpg. There's no life-cycle or average study, whatever those are. Just the relative amount of fossil fuel energy used to transport someone given some conditions. Anyone who eats food produced via industrial agriculture and uses that for energy to move themselves, also ends up using however much energy was required to get them that food via fossil fuels. If they live in a hut in the wilderness and hunt/grow all their own food, w/ no fossil fuel inputs needed, then they don't have a comparable equivalent fossil fuel efficiency, just like someone who grows fuel to power their own vehicle, assuming no fossil fuel inputs, has no coparable equivalent fossil fuel efficiency.

sherpa93

5 yr old article.... I think it quite an accomplishment for VW! This project was mothballed and recently brought back due to a 10 fold decrease in carbon fiber. I hope they make it. Best Ive been able to get on a motorized bike is 260 mpg (Merkan gallons) cruising at around 18 mph. So hats off to VW... Wind resistance on a bike/motorcycle is really horrendous. Aerodynamics plays a huge part in fossil and human powered efficiency. BTW metabolism/ Human fat is very potent stuff. On the energy density scale its 38. Jet fuel is 42.8. Turns out we humans are very good energy converters and storage units.. https://en.wikipedia.org/wiki/Energy_density

yes

That link is based on work by Pimentel. It is exactly what I am talking about, and is commonly grouped in the life cycle assessment field. Really, that is a subset of life cycle (energy return on energy investment).
It is an accounting of all fossil fuel used in production of the food, fueling the tractor, production of fertilizer, and pesticides, etc.

cerewa

We're complicated to fuel, though. We'd have some kind of breakdown rather rapidly if we tried to run on straight vegetable oil, and even more rapidly on pure ethanol, gasoline, or diesel. Sugar-water would get us a little further, but not that much.

lyeinyoureye

Embodied energy, that's what it is (finally remembered)!
The equivalent for a fossil fuel would be to multiply the mileage by .83, which is supposedly the efficiency of extraction/refining/transportation/equipment, and stuff like VO, depending on source, is the opposite in that it provides a lot of liquid energy output compared to fossil fuel energy inputs. Since the average calorie requires about seven of fossil fuels to produce, a rider getting the equivalent of ~700mpg in terms of energy they use via food/fat, only gets ~100mpg in terms of fossil fuel use since food production is fossil fuel intensive. While there is a significant portion of embodied energy for a new auto, if the bicycle uses significantly more fossil fuel energy per mile it may reduce the advantage garnered to the point of the auto using less energy over it's lifetime. Otoh, someone can double the apparent mileage of a bike by going 5mph instead of 15mph, or growing all their own food... Same goes for running an auto on oil based biofuels except to a far large degree.