Money doesn’t grow on trees, so it should stand to reason that diesel fuel wouldn’t grow on trees either. And yet the Brazilian Copaifera langsdorfii tree has been quietly producing a natural diesel variant in the tropical rainforest, something we’ve known about since the seventeenth century. It’s only now that farmers in Australia have decided to farm the tree on a large scale in the hopes of having 20,000 living, above-ground fuel wells.

Past owners of the notoriously wheezy diesel Rabbit will find it hard to believe, but this blurry streak is also powered by a four-cylinder diesel. Two of them actually: one for the front wheels and one for the rear. Built for use in front-loaders and forklifts, the 4.4-liter engines were specially tuned to 750 horsepower each by U.K. construction-equipment company JCB as part of an effort to set a new speed record for a diesel-powered car. It paid off.

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See a cool promotional video put together by Audi, featuring a time-lapse construction of the R10 TDI. Click here

During the 1980s, A diesel-powered Volkswagen Rabbit was briefly part of my household fleet. It was a particularly frigid Detroit winter, and we had to plug in the Rabbit's engine block heater if we were parked for even an hour or it absolutely refused to start. Even on warm days, our Rabbit hesitated at the touch of the ignition key. Its lack of power necessitated long-term planning for the simplest highway passing maneuvers. The engine clattered, smoked, and smelled like a city bus. The car's sole saving grace was that it traveled miles and miles on a single tank of fuel.