Students Build 2752 MPG Hypermiling Vehicle

MikeChino sends along this awe-inspiring excerpt: "Think claims of electric vehicles that get over 200 MPG are impressive? Try this on for size: a group of mechanical engineering students at Cal Poly have developed a vehicle that can get up to 2752.3 MPG — and it doesn't even use batteries. The Cal Poly Supermileage Team's wondercar, dubbed the Black Widow, has been under construction since 2005. The 96 pound car has three wheels, a drag coefficient of 0.12, a top speed of 30 MPH, and a modified 3 horsepower Honda 50cc four-stroke engine. It originally clocked in at 861 MPG and has been continuously tweaked to achieve the mileage we see today." It's not quite as street-worthy, though, as Volkswagen's 235 MPG One-Liter concept. Updated 20:01 GMT: The Cal Poly car's earlier incarnation achieved 861 MPG, not MPH; corrected above.

Comments

They say others did better

[mukund]

Not to steal their thunder (and this mpg result is old news), but according to their own blog, Universite Laval got 2757 mpg in that race. And Mater Dei High School hold the record with 2,843.4 mpg.

Rather pointless

[Solandri]

MPG is backwards. It tells you how much further you can go on a single gallon, not how much less fuel it'll take to cover a fixed distance. In practical terms, the latter is much more relevant to how people drive. If you buy a car which gets twice the MPG, you do not suddenly start driving twice as far every day. Your miles driven each day will probably remain fixed, so fuel saved is based on the inverse of MPG.

A consequence of this is that MPG exaggerates the benefit of highly fuel-efficient vehicles. 2752 MPG sounds like a lot. But switching from a 25 MPG vehicle to a 50 MPG vehicle saves you more gas than switching from a 50 MPG vehicle to a 2752 MPG vehicle. To cover a distance of 50 miles, the 25 MPG vehicle would consume 2 gallons. The 50 MPG vehicle would consume 1 gallon, for a savings of 1 gallon. The 2752 MPG vehicle would consume 0.018 gallons, for a savings of 0.982 gallons. This is less improvement than the switch from 25 MPG to 50 MPG. Because MPG is inverted, a 10 MPG improvement on a 25 MPG vehicle saves a lot more fuel than a 10 MPG improvement on a 2000 MPG vehicle.

Consequently, the most important thing for reducing overall fuel consumption is to get people out of gas guzzlers and into more fuel efficient vehicles. Stuff like hypermiling vehicles getting >2000 MPG are interesting from an engineering and design standpoint, but they serve little practical use. Even if you could develop a real car which got 2000 MPG, getting a single SUV driver to switch to a Prius would save 3.5x as much fuel as getting a single Prius driver to switch to this new ultra-high MPG vehicle.

This is why most of the rest of the world measures fuel efficiency in liters/100 km. It makes the amount of fuel your car will use for a typical drive pretty obvious, and makes it dirt simple to compare how much fuel you'll save switching to a different vehicle (just subtract the two numbers):
SUV = 16 liters/100 km
sedan = 9.4 liters/100 km
Prius = 4.7 liters/100 km
vehicle in article = 0.085 liters/100 km