100mpg cars - possible or not?

sophia8

Master Poster
sophia8
Joined
Oct 28, 2003
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OK, on another forum, I'm having a debate. This started with somebody posting on another list that, in the 60s, they actually knew a car engineer who had designed an engine that could do 100mpg; he had of course been "disappeared" by Big Oil (afraid for their profits) before he could show his plans or prototype to anyone.
The story's complete bull of course - when the finest engineering minds of our generation have so far been unable to devise such an engine for everyday transportation, it's not very likely that one unfunded maverick could have achieved that all on his own 40 years ago. I'm sure that this person existed, but he sounds like a typical fantasist who vamoosed once he realised that he would eventually have to produce this miracle engine.
However, what I'm asking here is: Is such an engine technically possible?
 
SAE Supermileage competition

IN 1991 I was involved in the SAE Supermileage competition. The vehicle we built took second place with 1083 MPG. The winner got about 1400 MPG. See http://students.sae.org/competitions/supermileage/ for more recent results.

Granted, the vehicle carried only 150 lbs at an average speed of 15 MPH, but you still get a pretty good idea of what could be done, if consumers didn't demand large heavy vehicles with high acceleration rates.

David
 
Way back when, the designer of the Mini-Cooper declared that he would be able to produce a car that would get 100mpg, go 100mph, and sell for 100 pounds.

He accomplished all goals. The 100mpg version was quite a production; stripped of nearly everything, with narrow, super-hard tires run on a slick "board" race-track with a fairing, and the engine run at a very high gearing.
But he did it.

Likewise to achieve 100mph, fairing, engine tuned to the teeth, changed gearing...but he could put it in the advertising without lying.
 
Bikewer said:
Way back when, the designer of the Mini-Cooper declared that he would be able to produce a car that would get 100mpg, go 100mph, and sell for 100 pounds.
Click to expand...

Alex Issigonis also sized the driver's door pockets of the Mini to hold a bottle of vermouth and a bottle of gin, so that the owner could always carry the ingredients to make a martini, his favourite drink.

Allegedly.
 
Hehe- I don't doubt it. This was an era when riders in Le Tour took a healthy swig of brandy before the final stage sprint.
 
Re: SAE Supermileage competition

dbowden said:
IN 1991 I was involved in the SAE Supermileage competition. The vehicle we built took second place with 1083 MPG. The winner got about 1400 MPG. See http://students.sae.org/competitions/supermileage/ for more recent results.

Granted, the vehicle carried only 150 lbs at an average speed of 15 MPH, but you still get a pretty good idea of what could be done, if consumers didn't demand large heavy vehicles with high acceleration rates.

David
Click to expand...

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I challenge that something was flawed in the determination of the mileage. I don't even think a lawn mower could get that kind of mileage.

Locally, a school set some record in a mileage test just like the one you speak of. It was over 1400 mpg. I called up the newspaper columnist who did the article to point out what the flaw was in proclaiming the mileage. The mileage test was over a very short distance, thereby multiplying greatly any kind of error in calculations someone perhaps made. I told him that those *small* gas powered motor scooters can only get about 80 mpg!!!! That's it! The flaw I thought of was how they measured the amount of gas in the vehicle and what got used. They probably forgot about the gas that originally went into the bowl of the carburetor, or something like that, it seemed to me. If you think about it...how could one of those lightweight Moped like scooters only get about 80 mpg, and one of these cars get over 1400? If you figure out how much fuel is burned per mile, it is some absolutely ridiculous amount that sounds unbelievable. This would be 128 oz. (3584 grams) of gas divided by 1400...or about 2 3/4? grams per mile. Do you realize what a gram weighs? It's like nothing!

Oh, I remembered something else I told him that I figured out about this so called test: Over the short course test, all they had to do is attain some speed and shut it off and coast. That's not a test! That's deception.
 
Re: Re: SAE Supermileage competition

Iamme said:
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I challenge that something was flawed in the determination of the mileage. I don't even think a lawn mower could get that kind of mileage.

Locally, a school set some record in a mileage test just like the one you speak of. It was over 1400 mpg. I called up the newspaper columnist who did the article to point out what the flaw was in proclaiming the mileage. The mileage test was over a very short distance, thereby multiplying greatly any kind of error in calculations someone perhaps made. I told him that those *small* gas powered motor scooters can only get about 80 mpg!!!! That's it! The flaw I thought of was how they measured the amount of gas in the vehicle and what got used. They probably forgot about the gas that originally went into the bowl of the carburetor, or something like that, it seemed to me. If you think about it...how could one of those lightweight Moped like scooters only get about 80 mpg, and one of these cars get over 1400? If you figure out how much fuel is burned per mile, it is some absolutely ridiculous amount that sounds unbelievable. This would be 128 oz. (3584 grams) of gas divided by 1400...or about 2 3/4? grams per mile. Do you realize what a gram weighs? It's like nothing!

Oh, I remembered something else I told him that I figured out about this so called test: Over the short course test, all they had to do is attain some speed and shut it off and coast. That's not a test! That's deception.
Click to expand...
dbowden was kind enough to post a link to the Supermileage page. Rules of the competition can be viewed there. These include descriptions of how the performance tests are carried out and how the fuel mileage is determined.

Did you read any of that before coming to your conclusion that, "something was flawed in the determination of the mileage"?
 
The VW Lupo, a normal compact production car on sale in Europe, runs on 80 mpg diesel. Just google it.

Over there they calculate fuel consumption in liters per 100 km instead of miles per gallon. The Lupo achieves 3 liters. The 100 mpg would be ~2.25 liters, so not to far off. And, unbelievably, the google calculator can convert "miles per gallon" into "liters per 100 km"!
 
Re: Re: SAE Supermileage competition

Iamme said:
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I challenge that something was flawed in the determination of the mileage. I don't even think a lawn mower could get that kind of mileage.

Locally, a school set some record in a mileage test just like the one you speak of. It was over 1400 mpg. I called up the newspaper columnist who did the article to point out what the flaw was in proclaiming the mileage. The mileage test was over a very short distance, thereby multiplying greatly any kind of error in calculations someone perhaps made. I told him that those *small* gas powered motor scooters can only get about 80 mpg!!!! That's it! The flaw I thought of was how they measured the amount of gas in the vehicle and what got used. They probably forgot about the gas that originally went into the bowl of the carburetor, or something like that, it seemed to me. If you think about it...how could one of those lightweight Moped like scooters only get about 80 mpg, and one of these cars get over 1400? If you figure out how much fuel is burned per mile, it is some absolutely ridiculous amount that sounds unbelievable. This would be 128 oz. (3584 grams) of gas divided by 1400...or about 2 3/4? grams per mile. Do you realize what a gram weighs? It's like nothing!

Oh, I remembered something else I told him that I figured out about this so called test: Over the short course test, all they had to do is attain some speed and shut it off and coast. That's not a test! That's deception.
Click to expand...

Well, I've just run through the numbers, and I figure an engine running on rails can get 4260 mpg, running at 15 mph, with 40 lbs of stuff, assuming 20% efficency. Normal tires, or a total weight of 400 lbs, might decrease that to 3000 mpg.

What is interesting is that even at speeds as low as these 95% (65% in the second case) of the drag is due to air resistance, and that's with a fairly generously-low drag coefficent of .25. That could be lower, as little as 0.15 though, if they have a good design.
 
Well, I've just run through the numbers, and I figure an engine running on rails can get 4260 mpg, running at 15 mph, with 40 lbs of stuff, assuming 20% efficency. Normal tires, or a total weight of 400 lbs, might decrease that to 3000 mpg. What is interesting is that even at speeds as low as these 95% (65% in the second case) of the drag is due to air resistance, and that's with a fairly generously-low drag coefficent of .25. That could be lower, as little as 0.15 though, if they have a good design.
Click to expand...

Unfortunately, we didn't even try to measure our Cd, but we did design the vehicle for a small and smooth of a frontal area as possible. I don't have a picture handy, but imagine a jet aircraft fuselage (with no wings), and you get an idea of the design. I don't recall the exact dimensions of the body, but I'd guess the diameter of our body was about 2 ft, which would give a frontal area in the neighborhood of pi ft^2. We also used Aerospoke ( http://www.aerospoke.com/ ) bicycle wheels (3) and high pressure (>100psi) tires to reduce rolling resistance as much as possible.

The rules of the contest do allow you to turn off the engine and coast, as long as you maintain an average of 15 MPH over the course. The mileage is computed over a distance of 9.6 miles, and you can see from the 2004 results that fuel usage ranges from about 13 to about 100 grams, weighed to the nearest .01 gram.

All vehicles begin with a 2HP Briggs and Stratton engine, to which significant modifications may be added. We converted our engine to overhead valves for more effecient combustion. However, we used a standard carburetor and magneto ignition system. I would guess that with greater control (fuel injection/electronic ignition) of the combustion timing, we'd have been able to get significantly better mileages.
 
Q---No I didn't read it. I would like someone to clearly explain how Mopeds then get such 'terrible' (relatively speaking) mileage. (or 4 horsepower lawnmowers for that matter...the very same engine used in the mileage test!!!)

I found the newspaper article from last May!! "No Gas Guzzler" is the title of it. North High School in Eau Claire set a record amongst 43 competing schools with a hybrid gas/electric vehicle. They 'averaged' 1610 mpg. The best run, in the average was 1814 mpg.

Get out! They said they could run to Mexico on $2 of gas! (last years gas prices...but still!) Ya, right. The 'car' (and it's not little either!!!It's about 2 feet wide and 8 feet long and shaped sort of bullet shaped, but more squared offf edges.) only used 4 milliters of gas! (Do you realize what a mililiter is??). It weighs (get ready) 240 pounds (article didn't say whether it counted the passenger)!!! not like 1 pound. It has bicycle wheels. The gas engine gets going and powers a generator which runs a battery which makes the car run. The engine is a 4 horsepower gas engine. (That's a lawnmower engine. (Note: My lawnmower runs out it's whole big tank after *quickly* mowing two postage size lawns!)

The test run course was 3 miles. It was the 12 th annual such test held at a university nearby. The teacher said it had the highest mileage of any vehicle ever. The students built the car of aluminum and 3 bicycle wheels. They borrowed parts from a forklift, truck, snowblower, bicycle, printer and motorcycle.

Um..sounds like Joe Newman and his (in)famous Energy Machine all over again. (look it up on the internet. We have discussed him here like 1-2 years ago or so!) Believe it or not, there were like 30!!Ph.D. people who backed Joe in his claim that his perpetual like energy machine (works on a similar principle as the bike where one thing runs a generator which then sends power back
to itself so that it could powsr the batteries and vehicle at the same time.

----------------

I still believe there is a flaw in what they think is happening. If that many Ph.D.'s were fooled (many to this day believe Joe's machine does as claimed hile other Ph.D.'s scoff that it goes against the law of entropy and the US Patent Office who has fought Joe for like 20 year or so on this claims it smacks of perpetual motion and will not grant him a patent, even though he has working machines!!! If somebody is being fooled here...why can't simple teachers be fooled with the bicycle test???? You can't tell me some vehicle could go to Mexico, on the level, no wind for only $2 of gas. (4 milliliters of gas, or whatever...an amount you'd have to practically ovbserve through a microscope) If they can., there indeed is some law of physics we don't understand...and Joe is right!

And I'm in a bad mood today, so watch out. My other mesage board is acting up and I am p****d.
 
Iamme said:
(4 milliliters of gas, or whatever...an amount you'd have to practically ovbserve through a microscope)
Click to expand...

1 ml = 1 cubic centimetre. Why would you need a microscope to see that?
 
Matibiri---excuse me while I find my glasses so that I can see 1 cubic centimeter.:D I was actually being a little tongue in cheek when I said the miliiliter thing. But I know there are many computer whizzes here at JREF that are good at bringing onto the screen...visuals.

Could anybody bring up a to-scale visual of 4 milliliters please?
 
If someone told me that some vehicle could get that kind of mileage from nuclear propulsion, I would believe it based on some preconceived assumption that nuclear packs into the tiniest mass, extreme power. But gasoline, per it's mass, is relatively docile (weak explosive force) stuff. Now nitromethane (top fuel and funny cars) is something else again!
 
Iamme said:
Could anybody bring up a to-scale visual of 4 milliliters please?
Click to expand...

4 ml:
4ml.jpg


1 l:
1000ml.jpg
 
I've calmed down a little now because my othr board is up and running. I have limited time on the boards per my work schedule. I will try to read the article(s) posted above when I get the chance. But can you understand my reasoning when I said how Joe Newman has got over 30 *Ph.D.* scientists to believe in his (similar machine)...yet you know it can't possibly be true?...so why would one believe in this bicycle claim stuff any more than that (Joe Newman Energy Machine)?

For you newbies...google for Joe Newman's Energy Machine for some very enlightening reading. (You will see the similarities here) I was so interested in this back nearly 20 years ago, that I got on Joe Newman's press release mailing list! His agent was Evan Soule'. I have a file folder on him! I saw Joe Newman when he was excitedly telling the world about his machine that one night on the Johnny Carson Show!
 
Current I'm getting 50 MPG in my Prius. There is a modification available, it voids the warranty, to add a tray of batteries in the trunk, which can be plugged in. Gives the car a 30 mile range using the gas engine only for assistence, possible to get if 100 MPG if your commute is under 30 miles between plug ins.

Not quite what you're talking about, but it's something is street legal and currently available.
 
Matabiri---Is the large black square the front face of a 4 milliliter cube? If so...can you imagine this 2 -4 thimblefull amount getting you to Mexico from about the Canadian border? Come on. If that was the cube off a nuclear rod, I'd almost have a hard time believing it.
 
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