Hydrogen Cars vs Lighter Cars?

Factual Questions
1

Obviously, President Bush’s recent “State of the Union” address has unleashed fierce debate over the area of existing petroleum based infrastructers vs those required to get hydrogen working as a viable option.

Such debate is a good thing, and yet, another debate attached to “reducing our reliance” on petroleum always seems to go unnoticed.

For example, in theory (and I’m only using this to illustrate my point) if legislation was passed that banned the automobile and forced everyone to ride motorcycles with sidecars, and/or mopeds - I think most reasonable people would agree our current world wide consumption of petroleum products would take a huge dive.

From what I understand, even the “biggest baddest” high horsepower bikes deliver far better mpg ratios that automobiles do they not?

Now I recognise my above suggestion isn’t realistic, but my point here is this - if automobiles weren’t anywhere near as heavy - if they weren’t made of steel, but rather, were totally made from composite materials (with the exception of the internal combustion engine of course) then a huge weight saving would take place - ergo greater power to weight ratios would be liberated - ergo less fuel burnt.

The current dependance of the Western World on high grade crude oil exposes a fundamental economic log jam - namely, supply versus demand. It seems to me, given the current existing infrastructures in place, the single easiest point of attack is to reduce our current levels of “demand” on petroleum products as averse to “hoping” that hydrogen cars will come sooner rather than later.

To give you an idea, apparently a dedicated Formula One car get down as low 500 kgs - without driver and fuel of course.

Conversely, a typical passenger car hovers at 1500 kgs - so you can see the sort of fuel savings which could be delivered with lighter cars - assuming of course you’re not ALSO trying to put in an 800hp engine capable of propelling you to 350km/h. :smiley:

In theory, less “demand” for fuel also delivers a concordant drop in our reliance on the “murky areas of supply” of pertroleum.

I personally would love to see a new range of vehicles produced which were made entirely of composite materials where various components could be upgraded over time as superior ergonomics and cockpit designs evolve. The ability to upgrade your “outer skin” as it were whilst maintaining your automobiles’ chassis and drive train would drastically change our current usage of resources and the energy used to “process” those resources into automobiles. This is a technological tangent which always seems to get overlooked - such is our love affair with the “fashion” aspects of which car we like to own. Within reason, the physical dimensions of passenger cars and SUV’s have evolved into fairly mature products. When we buy a new car, unlike upgrading some of the components in a Personal Computer, why do we have to buy every part of that new car from scratch? Cars are way more mature products than Personal Computers I would wager.

I’m the first to concede that things wear out, but in a vehicle, not everything wears out at the same rate. Imagine if you will, composite cars which allowed you to upgrade, or renew various components in your car with, say, a two or 3 day workshop turnaround? An entirely new dash and new leather seats for example, and a new stereo if your old one was playing up?

In short, with universally lighter cars, how much better off would would we be?

Also, with the exception of large trucks running into you, if all cars are lighter, they are safer apparently too due to their reduced kinetic energy. I’ve seen some pretty amazing “high speed walk aways” in motor racing over the last 20 years. Those carbon fibre monocoque tubs are awesome.

2

A lot.

I agree with what you say wholeheartedly. But it’s not going to happen. Carbon fiber is very expensive. Other materials are also expensive or have other down sides. But the biggest reason we won’t see it is that people don’t want it.
Look at the fuel efficient vehicles produced now and in the recent past. They don’t sell very well. Geo Metro’s didn’t sell. The “efficient” Civic’s didn’t sell. The current crop of hybrid’s don’t sell even when the company’s take a fairly large loss on each sale. Hell, I love small efficient cars and I still chose the “fast” engine over the “efficient” engine with literally twice the mpg. I use the difference in acceleration MAYBE once a week.
You can’t force people to buy lighter cars. Well you can, but they won’t and shouldn’t. What we probably should do is educate people. Or at least change popular culture into hating and feeling guilty about their SUV’s.

3

The problem with lighter cars is that they’re more expensive to produce. Carbon fiber ain’t cheap. There’s also all kinds of expensive enviromental problems with manufacturing things out of carbon fiber as some of the chemicals involved are pretty toxic. Also many lighter materials are difficult to work with. Titanium, for example, can’t be welded in an oxygen atmosphere and can only be welded in a sealed chamber filled with argon gas.

There’s also the conservatism of the engineers one has to overcome. They don’t like designing things with materials they’re not familiar with. There’s nothing quite like the feeling of having a design you’ve slaved over fail in unexpected ways simply because you chose to use a more exotic material than you normally would.

Finally, race cars aren’t designed like ordinary passenger cars. So comparing someone walking away from a 200 MPH crash in a race car (made out of any material) is pretty pointless. One could, in theory, build a car out of wood that would enable the driver to walk away from in the event of a 200 MPH crash, but that doesn’t mean it’d be practical to drive on the street.

Not that I’m railing against lighter cars, you understand, but there’s a reason why they’re not common, and are unlikely to be come so in the near future. Military aircraft have been built out of composite materials for a couple of decades now, but it’s only been fairly recently that you’ve seen the introduction of carbon fiber into high end cars (and then mainly as a decorative material, though there are exceptions to this, of course) because until now, no one could get the costs down to the point where folks could afford to buy a car built with such materials.

4

It’s easy to make cars lighter: just make them smaller. Most commuters’ needs can be met with a two-seater the size of a golf cart. Many commuters can get by with a single seater like the Corbin Sparrow.

5

Not me. An electric car does me no good, the range isn’t nearly long enough. Besides, for $15K , I can get a car that seats four! If cars like the Sparrow are going to take off, they need to get waaaay cheaper and have better performance.

6

I was only referencing the size of the Sparrow. If you put an 750cc engine on the Sparrow-sized (and shaped) vehicle, I bet you could easily beat the fuel efficiency, range, acceleration and price of a hybrid.

7

Tuckerfan? Just a friendly question? Is your name derived from your love of the famous “Tucker” automobile? If so, I’d love you to tell me more about that car one time… it had a 10 cylinder “boxer” helicopter engine in it, did it not?

Perhaps, another alternative to the Corbin Sparrow would be a similar vehicle in terms of size and shape and ergonomics, but with say, a 600cc motorcyle engine? Now THAT would fly! And it would have a really wicked range too. And I dare say it would probably be amazingly light as well. Possibly under 300 kgs?

8

Dopey me, scr4! You posted exactly what I suggested at exactly the same time!

9

I think the high cost is because there aren’ very many being built. if they were being prodced as much as regular cars the price would probably drop to around 8k

10

I dunno how well it would stand up to fifty thousand pounds of freight hitting it, being hauled by some vehicle that can hold freight off the road. Our highways are our freight transportation system. Rail doesn’t get 30% of the freight moved in the U.S.

OTOH in general I agree, that’d be why my F150 sits most of the time now, the saturn gets the ride.

11

I just watched this week’s “NOW with Bill Moyers.” I saw Leo DiCaprio and Cameron Diaz talking about how much they love their hybrid cars. They’re both small people, both single. They’re both driving tiny aluminum foil cars that cost much more than conventionally powered cars. Can either of those cars take a family of five on a week’s vacation, carrying all their luggage, and still reach highway speed in the space of an on-ramp? No. Sure, I’ll grant that the auto industry has been stodgy and resistant to change, but until somebody can produce a workable improbability drive, certain rules of physics will rule us.

12

Who says you need to use the same vehicle for a family vacation and a daily commute? For a married couple with three <16-yr old children, there’s no excuse for buying a minivan and an SUV. They could easily get by with a Toyota Prius 4-door hybrid plus a single-seater commuter, and renting a minivan for vacations.

13

Yeah, I took my user name from the car. It had a 6 cylinder helicopter engine in it. Ironically enough, the engine maker is still in business. (The engines are now built in Poland.) Drop me an e-mail and I’ll be happy to answer your questions.

Sock Munkey, 8K is still too pricey for one of those things. Why should I shell out that much money for a single seater when for the same amount (or less) I can buy a used Toyota that seats five? No, if a hybrid like the Sparrow is going to take off and be popular there’s only two ways it can happen: People are forced to buy them (not a good thing) or the cars are so cheap to buy that people want to buy them. Get them down to about 3K or less and you won’t be able to make 'em fast enough, otherwise, the only way to get people in 'em is to have an economic benefit to owning one.

14

There was recent show car that had 12 or 16 cylanders, developed 1000HP and still got 20MPG.

Can’t they design a car that has 200HP and gets 60MPG?

My 10 year-old Geo Prizm gets ~30MPG. By no means is it a huge car. but I’m still amazed that most new cars don’t get as good of milage.

Brian

15

It’s not that simple, because the “1000 HP engine” cannot do 1000 HP and 20 MPG at the same time. The 1000 HP is the peak power output you get when you rev it up all the way. 20 MPG is the fuel economy when the car is at a steady cruising speed and engine is running at a much lower RPM and power output, probably less than 100 HP. If you use a 200HP engine it would still have to do the same power (100 HP or so) to maintain a cruising speed.

16

scr4’s right. On the car in discussion, the engine shuts off cylinders when they’re not needed.

17

Another factor in making cars smaller and lighter is the cargo space. What good is a car to you if you can’t get two bags of groceries home in it? Cars like the Sparrow could only be used for commuters working in large cities, where space is limited. Just as long as the driver doesn’t need any more than a briefcase and laptop for his or her job.

18

I reckon Tuckerfan is right. And thank you to all of you in particular who answered my questions regarding the pollutants involved in the mass production of carbon fibre composites - I wasn’t aware of the nasty byproducts involved at that level.

As I said, I reckon Tuckerfan hit the nail on the head. If you could mass produce a “Sparrow” type jigger with say, a 750cc motorbike engine in it for $3000 US, that ALSO had air conditioning and luggage space for a set of golf clubs (as a reasonable example of a resonable requirement), then you’d probably have a demon little jigger with a fair amount of wicked squirt but ALSO had the little creature comforts you’d want in terms of cooling and heating etc.

Possibly a solution would be to provide a “non sales tax” incentive in some way that subsidises the cost of producing and purchasing such a vehicle.

Certainly, at a theoretical level, anything which can go towards producing mass transport which competes with existing comfort and safety levels and yet ALSO provides far lower fuel consumption has got to be a good thing… surely?

19

I should add that in Japan, the government does encourage small automobiles. There is a category of “light automobiles” which are limited to 660 cc engines and a certain size. You can buy a new one for under $8,000 and the registration/tax is about half that of a regular automobile. Unfortunately there is no fuel economy limit, so manufacturers tend to go maximize power rather than fuel economy. 660 cc engines aren’t very efficient if you add turbo and 5 valves per cylinder.

20

It would be interesting to note, however, what the sum total of consumption in gallons alone for one of those suckers is?

My point being, even if those Japanese engines are tuned towards horsepower as averse to frugality, if they’re using less fuel “overall” in any given week compared to a much larger heavier passenger car, then we’re all still in front, aren’t we?

I notice that most production 750cc motorbikes nowadays easily surpass 100bhp at peak usage - and as we’ve noted - peak usage is rarely used. I’m sure if we could produce a “Sparrow” type vehicle which was tuned towards performace that ALSO met the price barrier, we’d have a viable alternative for folks to use a vehicle which both “rips” along but uses less fuel overall.

And from what I hear, most motorbike engines are pretty finely tuned little jiggers - as in they seem to burn very cleanly and their exhaust pipes seem to always be rather “silvery” in appearance - indicating optimum fuel-air ratios.

I reckon if you could make a “Sparrow” type vehicle with reasonable luggage capacity and still get it under 300kgs with a 750cc or lo and behold, even a Suzuki GSX-R1100 engine (woo hoo!) you’d have a real wicked little rocket which still delivers sparkling mpg ratios.

Obviously, you’d probably be wanting to use an all aluminium chassis and outerskin, but I think we could do it.

Whaddya think?