There are at least three methods to run a diesel motor on biofuel utilizing vegetable oils, animal fats or both. All three are used with both fresh and used oils.

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

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

3. Convert it to biodiesel.

The very first two approaches sound most convenient, but, as so frequently in life, it's not quite that simple.

1. Mixing it

Vegetable oil is much more viscous (thicker) than either petro-diesel or biodiesel. The purpose of blending it or blending it with other fuels is to decrease the viscosity to make it thinner so that it flows more easily through the fuel system into the combustion chamber.

If you're mixing veg-oil with petroleum diesel or kerosene (like # 1 diesel) you're still using fossilfuel-- cleaner than the majority of, however still not clean enough, lots of would state. Still, for every single gallon of

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

People use numerous mixes, ranging from 10% veggie oil and 90% petro-diesel to 90% grease and 10% petro-diesel. Some people just utilize it that method, begin up and go, without pre-heating it (that 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 an extremely tough and tolerant motor-- it will not like it but you most likely won't eliminate it. Otherwise, it's not sensible.

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

Blends with numerous solvents and/or with unleaded fuel are "speculative at finest", little or nothing is understood about their results on the combustion characteristics of the fuel or their long-term effects on the engine.

Higher viscosity is not the only issue with utilizing vegetable oil as fuel. Veg-oil has different chemical homes and combustion qualities from the petroleum diesel fuel for which diesel motor and their fuel systems are developed.

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

They're hard but they'll only take so much abuse. There's no warranty of it, however utilizing a mix of approximately 20% veg-oil of great quality is said to be safe enough for older diesels, particularly in summer.

Otherwise using veg-oil fuel needs either an expert SVO option or biodiesel. Mixes and blends are typically a poor compromise. But mixes do have a benefit in cold weather condition.

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