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

1. Use the oil simply as it is-- usually 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 fuel;

3. Convert it to biodiesel.

The very first two techniques sound easiest, but, as so frequently in life, it's not quite that basic.

1. Mixing it

Vegetable oil is a lot more thick (thicker) than either petro-diesel or biodiesel. The function of blending it or blending it with other fuels is to decrease the viscosity to make it thinner so that it streams more freely 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 many, however still unclean enough, lots of would say. Still, for each gallon of

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

People utilize different mixes, ranging from 10% grease and 90% petro-diesel to 90% grease and 10% petro-diesel. Some people simply use it that way, launch and go, without pre-heating it (which makes veg-oil much thinner), or even utilize pure vegetable oil 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 very tough and tolerant motor-- it will not like it but you most likely will not kill it. Otherwise, it's not sensible.

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

Blends with numerous solvents and/or with unleaded gas 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 vegetable oil as fuel. Veg-oil has various chemical homes and combustion qualities from the petroleum diesel fuel for which diesel engines and their fuel systems are designed.

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

They are difficult but they'll only take a lot abuse. There's no assurance of it, but utilizing a blend of as much as 20% veg-oil of good quality is stated to be safe enough for older diesels, especially in summer season.

Otherwise utilizing veg-oil fuel needs either an expert SVO solution or biodiesel. Mixes and blends are usually a poor compromise. But blends do have a benefit in winter.

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