Hyper efficient cars near the X Prize finish line; liquid fuel/electricar battle revisited

It turns out that building a four-seater car that can get 100 miles to the gallon isn't easy.

Even if you offer a $10 million prize to do it.

(Image: the Edison2 car, a four-seater with a single-cylinder turbocharged engine. Credit: Edison2.)

With all the interest in bringing electric cars to Hawai'i from folks like Korean carmaker CT&T, and Project Better Place, it's interesting to look at the future of high fuel-efficiency vehicles. It turns out a lot of them are electric--but it also turns out there's a new view on powerplants.

The Progressive Insurance Automotive X Prize offered $10 million to build a car that could go 100 miles on a gallon, and it got lots and lots of interest. Dozens of companies, colleges, backyard shops, high school shop classes and innovative entrepreneurs hopped up to say they could do it.

Ultimately, 26 vehicles were accepted into the testing, which is conducted by Consumer Reports. The testing includes such requirements as that the car be able to run the required distance and that it's stable enough to be safe for the highway (for example, it doesn't flip over on a sharp turn).

There are also emissions tests, fuel economy tests, and ultimately, the requirement that the car be able to run for hours, getting the required 100 miles to the gallon (or in the case of vehicles run on electricity, fuel cells or other non-gas engines the equivalent.)

But after two rounds of testing, there's only one team—which has two vehicles—still in the running for the Mainstream class prize for a traditional four-seat, four-wheeled car that mainstream consumers might buy.

Another 13 vehicles are still alive in the Alternative class, which includes all kinds of interesting cars with two or three wheels, generally seating two people instead of four. Here is the rundown on the standings so far.

The final phase of testing will take place during the last two weeks of July at the Michigan International Speedway, and the X Prize is to be issued in September.

Cars don't need to be gasoline fueled. They can be run on alternative fuels, and even electricity. Indeed, a lot of the alternative cars are electric cars.

The remaining competitor in the Mainstream class is a team called Edison 2, which has two versions of its “Very Light Car,” which are both powered by internal combustion engines.

The cars run a single-cyclinder, turbocharged 40-horsepower power plant. It uses E85, which is 85 percent ethanol and 15 percent gasoline. And as the photo above shows, it's not your grandmother's Oldsmobile.

The Edison2 team is largely made up of sports car racers. Their cars seat four, have room for your luggage, and advertise a top speed of 100 miles an hour. They have a 6.5-gallon fuel tank, and before you worry that this is just too small, Edison2 says the cars have a range of 600 miles.

The key, according to the Edison2 website, is weight and wind resistance. So they worked very hard to build an aerodynamically efficient shape, and to cut weight wherever possible. For example, they used carbon-fiber instead of metal in some places, and managed to cut the weight of brakes from a pound to a few ounces.

They also claim the car is more recyclable than most.

The remaining cars in the competition are broken into two alternative classes, one for vehicles with side-by-side seating and one with tandem seating—one in front of the other. Edison2 also has a car in this group. Here's the list from the X Prize folks, listed by team name, car name, where they're from and how their car is powered.

Alternative Class - Tandem
Commuter Cars, Tango (Spokane, WA) Battery Electric
Edison2, Very Light Car #95 (Charlottesville, VA) Internal Combustion Engine
Spira, Spira4u (Carrollton, IL/Banglamung, Thailand) Combustion Engine
X-Tracer, E-Tracer 7002 (Switzerland) Battery Electric
X-Tracer, E-Tracer 7009 (Switzerland) Battery Electric

Alternative Class - Side-by-Side
Amp, amp'd Sky(Cincinnati, OH) Battery Electric
Aptera, Aptera 2e (San Diego, CA) Battery Electric
Li-ion Motors, Wave II (North Carolina) Battery Electric
RaceAbout Association, RaceAbout (Finland) Battery Electric
Tata Motors, Indica Vista EV X (Coventry, UK) Battery Electric
TW4XP, TW4XP (Italy) Battery Electric
Western Washington University, Viking 45 (Bellingham, WA) Gas/Electric Hybrid
ZAP, Alias (Santa Rosa, CA) Battery Electric

One of the odd features of the competition is that most of the cars are electric, but the only competitor still standing in the Mainstream class uses a liquid fueled engine. From the Edison2 website, here's their explantation for that.

“Edison2 entered the X Prize accepting the conventional wisdom that success would require an electric or hybrid electric drive. In fact, this assumption underlies our name, Edison2.

“Examination of the interplay between weight, drag, regenerative braking and acceleration, however, demonstrated to us the key importance of low weight and low aerodynamic drag in automobile efficiency, and led us away from a hybrid or electric drivetrain.”

Indeed, the competitor says, the heavy batteries required in an electric car work against the vehicle's fuel economy. The company blog says six pounds of gas has the energy contained in 500 pounds of battery.

Many teams think outside the box to reach the electric car conclusion. Interestingly, this team thought outside that box, and got back into the original box.

© Jan TenBruggencate 2010