The Automotive X Prize has announced who's in the race to build a production-ready car that tops 100 mpg, and the Tesla Motors, Aptera and German dieselmeisters Loremo are among the 66 entrants.

The Automotive X Prize formally announced the entrants, the $10 million purse and its official sponsor - Progressive Insurance - at the New York International Auto Show - and the competition's drawn teams from nine countries.

The biggest name is Tesla Motors, which saw its all-electric Roadster start rolling off the assembly line on Monday. We've long known Aptera was a contender with its super-sleek Cessna-like three-wheeler (that's it in the picture). Loremo - for low resistance mobile - uses a tiny two-cylinder diesel engine in a 990-pound car to deliver 157 mpg. So far, none of the major automakers has signed up, but teams have until later this year to join the fun.

Aptera photo by Wired.

Loremo's entry; photo courtesy Loremo AG.

The AXP has set the bar pretty high, and the competition is divided into two categories. Mainstream cars must carry at least four people and have all the comforts you'd expect in a production vehicle, including air conditioning, a stereo system and 10 cubic feet of cargo space. They've got to have four wheels, go from zero to 60 mph in under

12 seconds, hit at least 100 mph and have a range of 200 miles. In other words, it's got to be something people would buy.

That's the point, says Dr. Peter H. Diamandis, chairman and CEO of the X Prize Foundation. The cars must meet market needs for price, size, capability, safety and performance. The contest "is a call to action to promote and inspire innovation," he said. "The environmentally friendly cars created as a result of this competition will affect everyone who drives in ways we can't even imagine today."

The Tesla Roadster we all love so much; photo courtesy Tesla Motors.

The rules are only slightly less stringent for alternative vehicles.

They must carry at least two people, hit 80 mph and have a range of 100

miles or better. They can have any number of wheels. Five cubic feet of cargo space - about what you'd get with a Mazda MX-5 Miata - is required.

All vehicles must surpass 100 mpg an equivalent amount of energy if powered by electricity, hydrogen, solar or any other fuel. You can see all the guidelines here.

Entrants will have to prove their mettle during two long-distance stage races in

2009 and 2010. The contest will include a qualifying race and the "Grand Prize Final Race" that will combine speed, distance, urban driving and overall performance.

New York Mayor Michael Bloomberg said the Big Apple will host the first stage in September 2009. Its a safe bet Detroit will see a stage, and car-crazy Los Angeles seems like a lock since the X Prize Foundation is based in Santa Monica. Progressive is based in Mayfield Village, Ohio - might we see a stage there too?

The courses will "reflect typical consumer driving patterns," contest officials said, and reflect real-world terrain, conditions and weather. In other words, these cars won't be trailer queens hauled to a track somewhere. They'll be flogged mercilessly.

The prize will be divided 3:1 between the winners of the mainstream and alternative classes. First place in each division goes to the team that has the lowest overall time for all stages and meets or exceeds the 100 mpg equivalent standard.

You can read about the AXP and two teams - Aptera and Illuminati Motor Works - in Eric Hagerman's story "1 Gallon of Gas, 100 Miles - $10 million: The Race to Build the Supergreen Car."

Read the press release and see a complete list of teams here.