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

1. Use the oil simply 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 fuel;

3. Convert it to biodiesel.

The first two approaches sound simplest, but, as so often in life, it's not quite that easy.

1. Mixing it

Grease is far more viscous (thicker) than either petro-diesel or biodiesel. The function of mixing it or mixing it with other fuels is to reduce the viscosity to make it thinner so that it streams more easily 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 most, however still unclean enough, many would say. Still, for every single gallon of

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

People utilize different blends, varying from 10% veggie oil and 90% petro-diesel to 90% vegetable oil and 10% petro-diesel. Some people just use it that method, launch and go, without pre-heating it (which makes veg-oil much thinner), or perhaps utilize pure grease 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 very hard and tolerant motor-- it will not like it however you probably will not kill it. Otherwise, it's not wise.

To do it correctly you'll need 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 gasoline are "experimental at finest", little or absolutely nothing is understood about their impacts on the combustion qualities of the fuel or their long-term effects on the engine.

Higher viscosity is not the only issue with utilizing veggie oil as fuel. Veg-oil has various chemical residential or commercial properties and combustion qualities from the petroleum diesel fuel for which diesel engines and their fuel systems are designed.

Diesel engines are state-of-the-art makers with really precise fuel requirements, particularly the more modern, cleaner-burning diesels (see The TDI-SVO debate).

They are difficult however they'll only take a lot abuse. There's no assurance of it, but utilizing a mix of up to 20% veg-oil of great quality is said to be safe enough for older diesels, particularly in summertime.

Otherwise using veg-oil fuel requires either an expert SVO service or biodiesel. Mixes and blends are typically a poor compromise. But mixes do have an advantage in winter.

Just like biodiesel, some kerosene or winterised petro-diesel fuel blended with straight veggie oil lowers the temperature level at which it starts to gel. (See Using biodiesel in winter season) More about fuel blending and blends.