There are at least 3 methods to run a diesel engine on biofuel using vegetable oils, animal fats or both. All 3 are utilized with both fresh and pre-owned oils.

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

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 2 methods sound simplest, however, as so frequently in life, it's not quite that easy.

1. Mixing it

Grease is a lot more viscous (thicker) than either petro-diesel or biodiesel. The purpose of mixing 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 (same as # 1 diesel) you're still utilizing fossilfuel-- cleaner than a lot of, however still not clean enough, lots of would say. Still, for every single gallon of

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

People utilize numerous mixes, ranging from 10% grease and 90% petro-diesel to 90% veggie oil and 10% petro-diesel. Some people simply utilize it that way, begin up and go, without pre-heating it (that makes veg-oil much thinner), or even use pure grease without pre-heating it, which would make it much thinner.

You might get away with it with an older Mercedes 5-cylinder IDI diesel, which is a really difficult and tolerant motor-- it won't like it but you probably will not eliminate it. Otherwise, it's not smart.

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

Blends with different solvents and/or with unleaded fuel are "experimental at best", little or nothing is known about their results on the combustion attributes of the fuel or their long-term impacts on the engine.

Higher viscosity is not the only problem with utilizing vegetable oil as fuel. Veg-oil has different chemical residential or commercial properties and combustion characteristics from the petroleum diesel fuel for which diesel motor and their fuel systems are developed.

Diesel engines are high-tech devices with really precise fuel requirements, specifically the more contemporary, cleaner-burning diesels (see The TDI-SVO controversy).

They are difficult but they'll just take a lot abuse. There's no assurance of it, but using a blend of approximately 20% veg-oil of excellent quality is stated to be safe enough for older diesels, particularly in summer season.

Otherwise utilizing veg-oil fuel needs either a professional SVO service or biodiesel. Mixes and blends are generally a poor compromise. But mixes do have an advantage in cold weather condition.

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