In this episode, we find Top Gear's inimitable Jeremy Clarkson attempting to squeeze every last drop of derv out of an unmodified diesel-powered production car in an effort to travel 800 miles on a single tank.

This is a challenging enough proposition as it is, but Clarkson isn't messing about in some oil-burning microcar, he's doing it in an Audi A8 motivated by a 4.0-liter twin-turbo V8 diesel... not exactly a thrift-minded machine. In fact, it's a torque-monster lashed to a gigantic luxury car... something of a middle-finger to the Prius set.

Given that Clarkson doesn't resort to NASCAR-style bump drafting, aero fairings, or weight-stripping, he resigns himself to trundling about with the engine never turning over 1,200 RPM (that, friends, is discipline). In fact, Clarkson's forced to be such a skinflint that he runs around with virtually all of the A8's considerable creature comforts off, and even answers nature's call with a plastic bottle in an attempt to avoid having to stop.

So.. can he eke out 800 miles? Check out Part 1 and Part 2 of his magical miserly tour to find out.

[Source: TopGear via Youtube]