There are at least 3 methods to run a diesel engine on biofuel utilizing veggie oils, animal fats or both. All three are used with both fresh and used 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 very first two techniques sound easiest, however, as so often in life, it's not rather that basic.

1. Mixing it

Vegetable oil is a lot more viscous (thicker) than either petro-diesel or biodiesel. The purpose of blending it or blending it with other fuels is to lower 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 (same as # 1 diesel) you're still using fossilfuel-- cleaner than a lot of, but still unclean enough, numerous would state. Still, for every single gallon of

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

People utilize numerous mixes, ranging from 10% veggie oil and 90% petro-diesel to 90% grease and 10% petro-diesel. Some individuals simply utilize it that method, launch and go, without pre-heating it (which makes veg-oil much thinner), or perhaps use 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 a very hard and tolerant it won't like it but you probably won't 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, ideally utilizing pure petro-diesel or biodiesel for starts and stops. (See next.) In which case there's no requirement for the blends.

Blends with various solvents and/or with unleaded gasoline are "experimental at best", little or nothing is understood about their results on the combustion attributes of the fuel or their long-term results on the engine.

Higher viscosity is not the only issue with utilizing grease as fuel. Veg-oil has various chemical homes and combustion qualities from the petroleum diesel fuel for which diesel motor and their fuel systems are developed.

Diesel engines are state-of-the-art devices with very exact fuel requirements, particularly the more contemporary, cleaner-burning diesels (see The TDI-SVO controversy).

They're tough however they'll only take a lot abuse. There's no warranty of it, however utilizing a mix of up to 20% veg-oil of excellent quality is stated to be safe enough for older diesels, particularly in summertime.

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

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