From the cold weather in the mid west now (it's 75 hear in L.A.) many are talking about blending fuels. Many get the term flammable and combustible mixed up. A flammable liquid needs a flame or spark to ignite it (like gasoline, kerosene, alcohol, methanol, ethanol, etc). A combustible liquid needs compression or heat to ignite it (like kerosene, Diesel, veggie oil, animal fat oil, etc). The flash point of veggie oil and Diesel is around 650 degrees, so with the 1000 degrees of combustion temperature created inside the Diesel engine, it is easy to see why the engines work so well. If you heat Diesel up to about 120 degrees, then you can also ignite Diesel with a spark (point at which it gets fumy enough). Good Luck, TomC