There are at least 3 methods to run a diesel engine on biofuel using veggie oils, animal fats or both. All three are used with both fresh and secondhand 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 mix it with a solvent, or with fuel;

3. Convert it to biodiesel.

The first two techniques sound simplest, however, as so typically in life, it's not rather that simple.

1. Mixing it

Grease is a lot more thick (thicker) than either petro-diesel or biodiesel. The purpose of mixing it or mixing 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 mixing veg-oil with petroleum diesel or kerosene (like # 1 diesel) you're still utilizing fossilfuel-- cleaner than many, but still unclean enough, lots of would state. Still, for each gallon of

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

People use various blends, varying from 10% vegetable 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), and even utilize pure veggie 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 an extremely difficult and tolerant motor-- it won't like it however you most likely will not kill it. Otherwise, it's not smart.

To do it properly you'll require what totals up to an SVO system with fuel pre-heating anyhow, 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 unleaded gas are "speculative at best", little or nothing is known about their results on the combustion characteristics of the fuel or their long-term impacts on the engine.

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

Diesel motor are state-of-the-art makers with really precise fuel requirements, specifically the more contemporary, cleaner-burning diesels (see The TDI-SVO debate).

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

Otherwise using veg-oil fuel requires either an expert SVO option or biodiesel. Mixes and blends are usually a poor compromise. But mixes do have an advantage in cold weather condition.

Just like biodiesel, some kerosene or winterised petro-diesel fuel blended 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.