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An independent study project to convert a 1982 Mercedes-Benz turbo diesel to run on straight vegetable oil.

Josh Munson and Ethan Dreissigacker

Why?

Automobiles are one of the leading sources of greenhouse gas emissions. This is becuase they burn petroleum based fuels, unlocking stored carbon from the ground and releasing it into the air. Vegetable oil is a "carbon neutral" fuel. This means that the plants from which it is made take in the same amount of carbon that is released when the fuel is burned.

How?

As for using veggie oil as a fuel... well that's simple. When Rudolf Diesel invented the diesel engine in 1892, he had designed it to run on vegetable oil. The Modern diesel engine requires little to no modification to run on straight vegetable oil. The only problem is that most vegetable oil is too thick at room temperature to run through fuel lines. There are two ways to solve this problem.

The first is to make the oil into bio-diesel. This involves a chemical process which separates the glycerin from the oil, and replaces it with an alcohol, such as methanol. Once this is done, the resulting fuel can be poured straight into your gas tank. However when you add methanol, you also add emissions.

The second way is to heat the veggie oil before it enters the engine. Heating the oil causes it to thin, so that it can flow through the necessary hoses. This is the only way that you can truly run your car on straight vegetable oil (SVO), and this is what we did on our Mercedes. The one problem with this method is that when you turn your car off, the hot veggie oil cools, and turns back into a gel inside the engine. This problem is solved by "purging" the engine with diesel fuel, or bio-diesel before you turn off the car. Because of this most cars that run on straight veggie oil have two fuel tanks.