An eco adventurer driving a diesel-powered Hyundai went from Adelaide to Sydney without refueling. And when he discovered a quarter tank of fuel remained, he drove another 300 kilometers before the fuel was drained. All totaled, Hans Tholstrup drove 1776 kilometers on 75 liters, which converts to 50.4mpg. The Hyundai Santa Fe is equipped with a common-rail turbo-diesel engine. Cruising speed was close to 55mph with a few downhill spurts at 62mph. To say Tholstrup is frugal with the throttle is an understatement, but he does achieve great mileage.