Traveling 1000 miles in style on a single tank of diesel

A Jaguar XJ, fitted with a twin-turbo V6 diesel engine, drove a total of 1000.2 miles before running the 22.45 gal tank dry. The car recorded an average fuel economy of 44.38 mpg, a number that would put many a gasoline powered sub-compact to shame. Even a few hybrids would be hard pressed to achieve this kind of gas mileage during highway driving. The combination of the advanced diesel engine with the lightweight aluminum body of the XJ made the journey possible. The driver effectively drove the length of the UK, after which he headed back to Jaguars HQ in Birmingham. I wonder if it would run just as well on biodiesel.
[Source: Motoring.Co.Za]