Diesel engines powered by pure vegetable oil...Sounds like an add from the back of a comic book. But in reality diesel engines can be powered by cooking oil with sometimes simple conversion. Before long there will be the smell of fryers in the air!

A driver talks about conversion of his diesel VW to run on cooking oil. He reports better mileage and quieter running. The conversion cost him about $1,900. From the NY Times.

Many vegetable oils have similar fuel properties to diesel fuel, except for higher viscosity and lower oxidative stability. If these differences can be overcome, vegetable oil may substitute for #2 Diesel fuel, most significantly as engine fuel or home heating oil.For engines designed to burn #2 diesel fuel, the viscosity of vegetable oil must be lowered to allow for proper atomization of fuel, otherwise incomplete combustion and carbon build up will ultimately damage the engine. Many enthusiasts refer to vegetable oil used as fuel as waste vegetable oil (WVO) if it is oil that was discarded from a restaurant or straight vegetable oil (SVO) or pure plant oil (PPO) to distinguish it from biodiesel.