The second Edison 2 vehicle has just completed the 200 mile range test in the Progressive Automotive X PRIZE – with fuel left in the tank. Nothing is official at this stage and some further hurdles remain before the official presentations in September, but given that Edison 2 is the only team remaining in its class and that the successful completion of Monday's Dynamic Safety testing is almost a formality for the vehicle, it's likely that Oliver Kuttner and his team will become the winners of the $5 million prize for the Auto X PRIZE Mainstream Class.

Kuttner estimates that the car ran at around 120 miles per gallon during the 4 hour / 200 mile test, which wasn't without its drama. The humid temperatures in Michigan posed a challenge for keeping the cars cool and one of the vehicles had to stop several times to have water tipped on the engine and undergo some minor air intake adjustments. In an example of just how finely tuned this vehicle is, the minor adjustment to the air intake brought the operating temperature down from 124 degrees to 89 degrees, allowing the car to continue running without further stops.

Despite empty stands at the Michigan International Speedway and cars traveling around the track at a fraction of the speed usually seen here, this is a momentous occasion and the the stakes are very high.

"It's the biggest prize in auto racing", said Edison 2 founder Oliver Kuttner, "Whoever wins the Brickyard this weekend won't be getting a check this size".

We'll keep you posted as results become official.

The outcome of the two Alternative Class sections (tandem and side by side) are much more difficult to predict and will almost certainly come down to a showdown during the Combined Efficiency and Performance Event next Tuesday.

After the finals the vehicles will undergo "Coast Down" at the Chrysler Proving grounds and "Validatio"n at Argonne National Labs before the X Prize is officially awarded at a ceremony in Washington DC in September.