With petrol prices rising, the Top Gear team give alternative advice on fuel economy on saving money by racing 5 supercars. The Ferrari 599, Lamborghini Murcielago, Mercedes McLaren, Aston Martin DBS and Audi R8 are all given one gallon of fuel; how far will they get around the track? And what about the Toyota Prius vs. BMW M3? Brilliant challenge video in high quality from BBC motoring show Top Gear, available to view in full on the BBC Top Gear YouTube channel. Visit http://www.TopGear.com for all the latest news and car reviews.