There are at least three ways to run a diesel motor on biofuel utilizing vegetable oils, animal fats or both. All three are utilized with both fresh and pre-owned oils.

1. Use the oil just as it is-- typically called SVO fuel (straight grease);

2. Mix it with kerosene (paraffin) or petroleum diesel fuel, or with biodiesel, or blend it with a solvent, or with gasoline;

3. Convert it to biodiesel.

The first 2 techniques sound easiest, but, as so often in life, it's not rather that basic.

1. Mixing it

Grease is a lot more viscous (thicker) than either petro-diesel or biodiesel. The function of blending it or blending it with other fuels is to lower the viscosity to make it thinner so that it flows more freely through the fuel system into the combustion chamber.

If you're mixing veg-oil with petroleum diesel or kerosene (exact same as # 1 diesel) you're still using fossilfuel-- cleaner than the majority of, however still not tidy enough, many would say. Still, for each gallon of

vegetable oil you use, that's one gallon of fossil-fuel conserved, and that much less climate-changing carbon in the atmosphere.

People use numerous mixes, varying from 10% veggie oil and 90% petro-diesel to 90% grease and 10% petro-diesel. Some individuals just use it that method, begin up and go, without pre-heating it (which makes veg-oil much thinner), and even use pure vegetable oil without pre-heating it, which would make it much thinner.

You may get away with it with an older Mercedes 5-cylinder IDI diesel, which is a really hard and tolerant motor-- it won't like it however you probably won't kill it. Otherwise, it's not smart.

To do it appropriately you'll require what amounts to an SVO system with fuel pre-heating anyhow, ideally utilizing pure petro-diesel or biodiesel for starts and stops. (See next.) In which case there's no requirement for the blends.

Blends with different solvents and/or with unleaded gas are "speculative at finest", little or absolutely nothing is known about their effects on the combustion characteristics of the fuel or their long-lasting results on the engine.

Higher viscosity is not the only issue with utilizing veggie oil as fuel. Veg-oil has different chemical homes and combustion attributes from the petroleum diesel fuel for which diesel engines and their fuel systems are designed.

Diesel engines are modern makers with very precise fuel requirements, especially the more modern, cleaner-burning diesels (see The TDI-SVO controversy).

They're difficult however they'll just take so much abuse. There's no assurance of it, but utilizing a mix of up to 20% veg-oil of excellent quality is stated to be safe enough for older diesels, especially in summertime.

Otherwise utilizing veg-oil fuel needs either an expert SVO solution or biodiesel. Mixes and blends are typically a poor compromise. But mixes do have a benefit in winter.

As with biodiesel, some kerosene or winterised petro-diesel fuel blended with straight grease reduces the temperature at which it starts to gel. (See Using biodiesel in winter) More about fuel mixing and blends.