With the new series of Top Gear having started recently over in England, the team decided that it was again time to look at fuel economy. A few years back, the show made the round trip from London to Edinburgh and back in an Audi A8 TDI on a single tankful of diesel fuel. Now, with fuel prices above $9 a gallon, they have decided to see which cars provide solid fuel economy numbers. This time around they are working on the premise that even those with lots of money to spend on a car might still want to get better mileage. Sure the premise is thin but we're talking about Jeremy Clarkson here. Rather than the usual Prius vs, everybody else routine, Clarkson and Crew decided it would be better to test some of the fastest cars in the world to see which could go the furthest on a gallon of gasoline. Literally a single gallon of gas. They took a Ferrari 599, Audi R8, Lamborghini Murcielago, Mercedes Benz SLR and an Aston Martin DBS and put in a gallon of fuel each. Then they raced them around the Top Gear track until they were empty. You can watch the video after the jump to see which was the thriftiest with its gas allotment. Be forewarned however, that none made it into double digit...