The X Prize Foundation, best known for sponsoring space travel competitions, on Thursday offered $10 million to make a super-efficient car.
At the New York International Auto Show, the foundation and sponsor Progressive Casualty Insurance announced the newly named Progressive Insurance Automotive X Prize. The competition, open to both established automakers and unknown engineers, is meant to result in "real cars" that are available for purchase, rather than concept cars.

More than 60 teams have for a signed up for the competition, including Aptera Motors and Tesla Motors, California electric-car manufacturers; Loremo, a German maker of diesel fuel cars; and a team from Cornell University, according to the Associated Press.
The winners will participate in a cross-country race in 2009, in which entries will be judged on fuel efficiency, speed, distance, and other factors. One entrant in the competition will be the air-powered car from MDI Motors, which will be developed in the United States by Zero Pollution Motors.