There are at least three ways to run a diesel engine on biofuel using 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 mix it with a solvent, or with fuel;

3. Convert it to biodiesel.

The first two approaches 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 mixing it or mixing it with other fuels is to reduce the viscosity to make it thinner so that it streams 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 many, but still unclean enough, many would say. Still, for every gallon of

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

People use different blends, varying from 10% grease and 90% petro-diesel to 90% grease and 10% petro-diesel. Some people simply utilize it that method, start up and go, without pre-heating it (that makes veg-oil much thinner), or perhaps use 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 tough and tolerant motor-- it won't like it however you probably won't eliminate it. Otherwise, it's not sensible.

To do it correctly you'll require what amounts 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 need for the blends.

Blends with numerous solvents and/or with unleaded fuel are "experimental at best", little or nothing is understood about their results on the combustion qualities of the fuel or their long-lasting impacts on the engine.

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

Diesel motor are state-of-the-art devices with extremely exact fuel requirements, specifically the more contemporary, cleaner-burning diesels (see The TDI-SVO debate).

They're difficult however they'll only take a lot abuse. There's no assurance of it, however utilizing a mix of up to 20% veg-oil of great quality is stated 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 blends do have an advantage in winter.

Just like 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 blending and blends.