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

1. Use the oil just as it is-- normally 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 very first two techniques sound most convenient, however, as so frequently in life, it's not rather that basic.

1. Mixing it

Grease is much more viscous (thicker) than either petro-diesel or biodiesel. The function of blending it or mixing it with other fuels is to reduce 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 (like # 1 diesel) you're still using fossilfuel-- cleaner than the majority of, but still not clean enough, numerous would say. Still, for each gallon of

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

People utilize various mixes, ranging from 10% grease and 90% petro-diesel to 90% grease and 10% petro-diesel. Some individuals simply utilize it that method, launch and go, without pre-heating it (that makes veg-oil much thinner), or even utilize pure veggie 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 very hard and tolerant motor-- it will not like it however you probably won't eliminate it. Otherwise, it's not wise.

To do it correctly you'll require what totals up to an SVO system with fuel pre-heating anyway, ideally using pure petro-diesel or biodiesel for starts and stops. (See next.) In which case there's no need for the blends.

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

Higher viscosity is not the only problem with using veggie oil as fuel. Veg-oil has different chemical properties and combustion attributes from the petroleum diesel fuel for which diesel engines and their fuel systems are developed.

Diesel motor are high-tech devices with really accurate fuel requirements, particularly the more contemporary, cleaner-burning diesels (see The TDI-SVO debate).

They are difficult however they'll just take a lot abuse. There's no warranty of it, but using a blend of up to 20% veg-oil of good quality is said to be safe enough for older diesels, especially in summer season.

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

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