There are at least 3 ways to run a diesel motor on biofuel using 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-- generally 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 first 2 techniques sound simplest, however, as so frequently in life, it's not rather that basic.

1. Mixing it

Vegetable oil is far more thick (thicker) than either petro-diesel or biodiesel. The function of mixing it or blending it with other fuels is to lower 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 (same as # 1 diesel) you're still utilizing fossilfuel-- cleaner than the majority of, however still not tidy enough, many would say. Still, for every 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 use various blends, ranging from 10% grease and 90% petro-diesel to 90% grease and 10% petro-diesel. Some people simply utilize it that method, begin up and go, without pre-heating it (which makes veg-oil much thinner), and even utilize 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 an extremely difficult and tolerant motor-- it will not like it however you probably won't eliminate it. Otherwise, it's not wise.

To do it properly you'll require what amounts to an SVO system with fuel pre-heating anyway, 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 and/or with unleaded gasoline are "experimental at best", little or absolutely nothing is understood about their results on the combustion qualities of the fuel or their long-term impacts on the engine.

Higher viscosity is not the only issue with using veggie oil as fuel. Veg-oil has various chemical homes and combustion characteristics from the petroleum diesel fuel for which diesel engines and their fuel systems are developed.

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

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

Otherwise utilizing veg-oil fuel needs either a professional SVO solution or biodiesel. Mixes and blends are generally a bad compromise. But blends do have a benefit in winter.

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