There are at least three methods to run a diesel motor on biofuel using vegetable oils, animal fats or both. All three are used 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 gasoline;

3. Convert it to biodiesel.

The first 2 approaches sound easiest, but, as so often in life, it's not rather that simple.

1. Mixing it

Grease is a lot more viscous (thicker) than either petro-diesel or biodiesel. The function of blending it or it with other fuels is to reduce the viscosity to make it thinner so that it flows more easily through the fuel system into the combustion chamber.

If you're blending veg-oil with petroleum diesel or kerosene (like # 1 diesel) you're still using fossilfuel-- cleaner than most, however still not clean enough, numerous would say. Still, for every 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 different mixes, ranging from 10% veggie oil and 90% petro-diesel to 90% grease and 10% petro-diesel. Some people simply utilize it that method, launch and go, without pre-heating it (which makes veg-oil much thinner), or even 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 really hard and tolerant motor-- it will not like it but you most likely will not eliminate it. Otherwise, it's not sensible.

To do it effectively you'll need what totals up 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 various solvents and/or with unleaded gasoline are "speculative at finest", little or absolutely nothing is understood about their impacts 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 properties and combustion attributes from the petroleum diesel fuel for which diesel motor and their fuel systems are developed.

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

They are difficult however they'll only take so much abuse. There's no assurance of it, however using a mix of up to 20% veg-oil of great quality is stated to be safe enough for older diesels, specifically in summer.

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

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