The Edison 2 is a well-deserved winner, having a 4-seat cab with enough internal space. the 1-cylinder turbocharged engine is low-cost and due to the very high fuel efficiency, can meet emission regulation with just simple EGR, thus help reducing cost further. Crash testing performance remains to be seen, but, with the high-strength steel tube construction (like NASCAR) having high strenght-to-weight ratio, with a fully caged body and lift-up canopy for entry like in an aircraft, frontal and side collision protection is likely to be good. Cross country driving under high wind may pose some problem, so the vehicle is best for urban use.

Kudos! The Edison2 team had 4 entries, because they were so determined to win it. Both of the final finalists in the Mainstream Class were from Edison2. They were astute in their design.

I think they went with E85 because its octane got them more horse power out of a tiny, lightweight engine.

They used a lot of carbon fiber, and I wonder how cost-effectively this car could be mass produced?

I also wonder how well it goes uphill with 4 occupants. With big enough gears, I guess anything is possible.

The popular mechanics interview they did indicated that they went with E85 simply because it gave the best chance of winning. They put winning as the top priority and something about the rules gave E85 a clear advantage in the way MPGe was calculated.

No, because we do not have cellulose yet.

could be something to do with the energy type content IE Petrol C8 H16 - to 18
Alcohol C2 H5 OH
For the same 'weight' the lower energy of Alc is offset by higher units of H as well as the useful Oxygen.
As well as the possibility of using higher compression ratios to extract more of the available energy.

Compared to the heavier vehicles, small engines generally are at a disadvantage especially below ~ 500cc's per cylinder. Although there may be advantages from a little as 250cc,that would be the low end of efficient cylinder designs.

Will this competition spur the Auto Industry into producing more energy efficient cars? I doubt it. I don't think there is going to be a market for cars that look like soap box derby racers. The message from this competition might be 'see what you have to give up in order to get 100 mpge'.
I could see the X-Tracer as a commuter car except for the high price.

You can see the curve, an HEV can get 50 mpg and these get 100 mpg. You can seat four in the HEV, go down the freeway and do what other cars do. Here you make compromises. Most consumers would like better mileage, but to not want to give up anything.

Hey, would the Xtracer get to use the car pool lane like a motorcycle (and have the attendant waivers from crash worthiness standards), or would those two little outrigger training wheels cause it to need 5mph bumpers and reinforced sidebars and such?

I sure wish my 10 yr old van could hold on for another 2 yrs, but I'll be happy if it makes it another 6 mos. It has gotten to the stage where we are taking on a policy of DNR - do not resuscitate. It has 190,000 miles on it. I sure wish there were a hybrid to replace it with. An electric van is probably further off than a reasonably priced electric car.

Oh well, maybe I'll buy a used one that can last for 5yrs, and hopefully electric/hybrid will be ready by then.

Car maker marketing departments have to show that they can sell 100,000 hybrid minivans per year, or they will not even consider it. You two get 99,998 others to go along and they just might make them.