Top Gear personality Jeremy Clarkson takes the Audi A8 twin-turbo diesel out for the ultimate test: driving from London to Edinburgh and than back for a total of 800 miles — on a single tank of gas. Videos after the jump.

Top Gear personality Jeremy Clarkson takes the Audi A8 twin-turbo diesel out for the ultimate test: driving from London to Edinburgh and than back for a total of 800 miles — on a single tank of gas. Videos after the jump.