There are at least three ways to run a diesel motor on biofuel using vegetable oils, animal fats or both. All 3 are used with both fresh and secondhand oils.

1. Use the oil just as it is-- typically called SVO fuel (straight veggie oil);

2. Mix it with kerosene (paraffin) or petroleum diesel fuel, or with biodiesel, or blend it with a solvent, or with gasoline;

3. Convert it to biodiesel.

The first 2 techniques sound most convenient, however, as so often in life, it's not quite that simple.

1. Mixing it

Vegetable oil is much more viscous (thicker) than either petro-diesel or biodiesel. The function of mixing it or blending 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 (like # 1 diesel) you're still using fossilfuel-- cleaner than a lot of, however still not tidy enough, numerous would say. Still, for every gallon of

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

People utilize numerous mixes, varying from 10% grease and 90% petro-diesel to 90% grease and 10% petro-diesel. Some people simply utilize it that way, start up and go, without pre-heating it (that makes veg-oil much thinner), or perhaps use pure veggie oil 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 hard and tolerant motor-- it won't like it however you probably will not kill it. Otherwise, it's not sensible.

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

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

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

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

They're tough but they'll only take so much abuse. There's no assurance of it, but using a mix of approximately 20% veg-oil of excellent quality is said to be safe enough for older diesels, specifically in summer.

Otherwise using veg-oil fuel needs either a professional SVO service or biodiesel. Mixes and blends are generally a bad compromise. But blends do have a benefit in cold weather.

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