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Eco-Marathon Team Hits 2,843 mpg
At this year's Shell Eco-marathon Americas event the team from Mater Dei High School shattered last year's record by traveling 2,843.4 miles on a single gallon of gasoline. "How did the Evansville, Ind., team come up with its winning airfoil-meets-teardrop design and beat out its largely collegiate competitors? "It comes from trial and error, seeing what works and what doesn't," an unidentified student and team member told a local newscaster Friday. Those top three vehicles, like most in the competition (25 out of 33 total), used internal combustion engines. The goal for all entrants was to travel as far as possible using as little fuel as possible. Vehicles--sans driver--couldn't weigh more than 160 kilograms (352 pounds), while drivers had to weigh at least 50 kilograms."
And adjusted their carburetor. Now it only gets 30 Miles per gallon.
What It could happen...
Ask not what you can do for your country. Ask what your country did to you
My 1963 car gets 40mpg. Sure it's an 2-cylinder NSU Sport Prinz but even the 1960s Darts I've had got 25-30mpg with a slant six.
I don't understand why modern cars get such lousy mileage.
riding round the world on an old motorcycle
Let us briefly pause whilst my 1988 Mercury Grand Marquis sputters loudly with contempt.
What's the conversion so that solar cars can get "MPG" of gasoline?
How do you measure miles per gallon on a non-gasoline-powered vehicle?
According to this video that's almost 10 times farther than a person could walk on a gallon of gasoline... if a person could metabolize gasoline, of course.
- Greg
Start a happiness pandemic
Weight.
Crash test standards add weight. Power windows, power-adjustable seating, 6-disc in-dash CD changers, power moonroof, they all add weight.
Colin Chapman, the founder of Lotus, pointed out that "Adding power makes you faster on the straights. Subtracting weight makes you faster everywhere." He was going for speed, but the same thing applies to fuel economy.
Consider a car that's a lot newer than those you mention: the 1985 Honda CRX. It had a 76-horsepower engine, and it had a 9.1-second 0-60, and 32 miles to the gallon. It was able to do that because it only weighed 1860 pounds.
1860's unthinkably light by current standards. I drive a Mustang GT that has a curb weight of something like 3860 pounds, so that's more than two tons with a driver and a tank of gas. You want a performance car that's even close to that 1860lbs, you end up with...a Lotus Exige, which is about 2000 lbs. And costs a hell of a lot more than an '85 CRX.
Also, an essential strategy for achieving high mileage is to burn the engine at optimum efficiency RPMs to quickly get to speed, and then use your mass combined with low aerodynamic and rolling losses to coast as long as possible (frequently almost to the point of stopping). This is why there are required average lap speeds and maximum speeds. Of course, this strategy could hardly be used in production vehicles or in public roads.
Second, modern cars have bigger engines. Even a tiny town car in Europe often now has a 100BHP engine when 20 years ago it would have been 60. More acceleration, more wasted power, plus the bigger engine just takes more power to turn over. Third, modern fuel has a lower octane rating than older fuel, and so must use a lower compression ratio - which means lower efficiency, as you find out in basic thermodynamics. Finally, air con,power steering, all need power to operate. Even the most basic model of possibly the most basic car in Europe - the Hyundia i10- has air con, power steering, and a 60HP plus engine.
Despite this, the best modern engines are remarkably good because of advances in fuel injection (both Diesel and gas), and because the timing cycles and better valve gear result in less port wastage. The real fuel consumption of that 2007 Diesel is about 80% of my 1990 non-turbo mechanically injected model of the same weight and size, which is pretty good.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
If you read the article, the top competitor using gasline got 163.5 MPG. It does say they used Internal Combustion Engines, and it doesn't say what they did use but it's not gasoline. It doesn't say whether that 2843 MPG is miles per gallon of some other fuel of if they gave them the engergy equivalent of 1 gas of gasoline in that "some other fuel" and measured how far they went on that. Or maybe it's something else completely. The article is poor on details.
Real programmers use "copy con program.exe"
Well, to start with, the anti-pollution devices don't make the engine more efficient. They eliminate unburned hydrocarbons and nitrous oxides. Sometimes these anti-pollution systems actually use available horsepower to do their jobs. In some cases they reduce the efficiency of the engine, in order to reduce emissions.
One good example is the catalytic converter. It is in the exhaust stream, post combustion (usually mounted under the floor of the car). It works by catalytically combining oxygen, often pumped in, with any unburned hydrocarbon (CO, for example). Having the catalytic converter in the exhaust system acts as a restriction. So, it requires power to pump the oxygen it needs to do it's job, and it reduces the engines efficiency by increasing back-pressure.
I think you get the idea. I've read that the pollution control hardware costs the typical vehicle a couple of miles-per-gallon in efficiency
As to no longer needing them, once you improve the efficiency... Well, now that the laws are in place requiring the emission control systems to be included, it's always harder to undo a law, so there will be very little effort in that reguard. No politician wants to be known as the one who submitted the bill to remove the emission control devices. Particularly in today's political climate. In fact, the trend is to go the other way: If the engine becomes more efficient then the emission control system should be able to remove even more unburned hydrocarbons and nitrous oxides; and, the requirements therefore become stricter.
How about a contest where the results can actually benefit a normal car?
http://www.progressiveautoxprize.org/
I have a 460hp (modded) car that got 38mpg on a LA-San Diego round trip. At the same time, it gets about 2mpg at full throttle and top speed. There is nothing wrong with modern engines, but if you have a ton of power and habitually use it, you will pay in fuel.
And do not forget, modern cars are heavier because of safety requirements, noise reduction materials, power everything, air conditioners, etc...
No good deed goes unpunished...
you've probably noticed already, but these are not practical vehicles. We're talking about single-person, prone-position, ground-hugging, 10-20 MPH vehicles. Of course you can get 2000+ MPG with those conditions! The Progressive Automotive X Prize is about practical vehicles getting 100 MPG (or equivalent). Now that's a race whose outcome is interesting! Check out some of the X Prize Cars which have already been designed.
augment your senses: http://sensebridge.net/
The reporter got it wrong (as usual). The single entry was actually running Liquefied Petroleum Gas (LPG) not as he reports "liquid petroleum gasoline". I believe the "combustion" class of which the winner was a part is plain old gasoline, just as the headline states.
It depends on a lot more then vehicle speed. Inaccurate blanket statements are an issue with mythbusters. Their conclusion is obviously constrained by several parameters including, but not limited to, wind spd, wind dir, vehicle geometry, AC size, AC COPR, AC control, temp, humidity, etc. Many of these may very well change the conclusion by less than 10%, while others have a serious influence. In any event, five 5 percents add up. That's my problem with mythbusters, they take the most laborious(boring) yet critical component out of experimentation: defining the problem & methodology. This is a good example because the conclusion is essentially worthless. Rather then celebrate science, they completely miss the point.
Its Shell sponsoring it, of course non-gasoline vehicles weren't eligible for the grand prize...
Damn corporate scams for cheap publicity and easy recruitment.
Hey, now, let's put this conspiracy theory through it's paces. So, Shell is hosting this competition for cheap publicity and easy recruitment, right? Then why would they rig the race -- the ultimate example of trying to earn bad publicity and discouraging recruitment? Or, if the rigging was hoping to promote gasoline while they still get cheap publicity and easy recruitment, by trying to imply that gasoline always wins or something (I'm trying to help your theory out here), then why did they allow other fuels compete at all? To make gasoline look bad so that they can then refuse to award them the prize?
It just doesn't make sense.
Look, oil companies have done a lot of bad things in the world -- some intentional, most unintentional, but still bad. But pretending that *everything* they do must have some sort of evil hidden motive to keep the world addicted to gasoline is just ridiculous. The other day, I sat down on a park bench that had a small plaque on the side that it had been donated by Shell. Clearly, that bench was an insidious attempt to get Americans to stop walking so that they become fat and lazy and need big SUVs to support their exercise-averse lifestyle, right?
Things like this serve many purposes. Some of them can get tax deductions. Some of them are an attempt to earn good PR or recruit. Some of them are, to be quite honest, a way to allow execs to feel all warm and fuzzy that they're doing good things in the world while they keep the oil flowing. But the concept that everything they do must be a plot to keep us hooked on gasoline is just dumb.
I'll BUILD someone to replace you. Some kind of gamma-powered monster, with a heart as black as coal!