There are at least 3 ways to run a diesel engine on biofuel utilizing vegetable oils, animal fats or both. All 3 are utilized with both fresh and secondhand 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 mix it with a solvent, or with gasoline;

3. Convert it to biodiesel.

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

1. Mixing it

Vegetable oil is a lot 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 (very same as # 1 diesel) you're still utilizing fossilfuel-- cleaner than the majority of, but still unclean enough, many would say. Still, for every gallon of

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

People utilize numerous blends, varying from 10% vegetable oil and 90% petro-diesel to 90% grease and 10% petro-diesel. Some individuals simply utilize it that method, start up and go, without pre-heating it (that 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 really hard and tolerant motor-- it won't like it but you most likely won't kill it. Otherwise, it's not wise.

To do it correctly you'll need what amounts 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 mixes.

Blends with numerous solvents and/or with are "experimental at best", little or absolutely nothing is learnt about their effects on the combustion attributes of the fuel or their long-lasting impacts on the engine.

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

Diesel motor are high-tech machines with extremely accurate fuel requirements, particularly the more modern-day, cleaner-burning diesels (see The TDI-SVO debate).

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

Otherwise using veg-oil fuel needs either a professional SVO option or biodiesel. Mixes and blends are usually a bad compromise. But blends do have an advantage in winter.

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