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

1. Use the oil simply as it is-- normally 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 gas;

3. Convert it to biodiesel.

The first two methods sound most convenient, however, as so typically in life, it's not rather that basic.

1. Mixing it

Grease is much more viscous (thicker) than either petro-diesel or biodiesel. The purpose of mixing it or mixing it with other fuels is to lower 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 (exact same as # 1 diesel) you're still utilizing fossilfuel-- cleaner than many, but still unclean enough, numerous would say. Still, for every gallon of

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

People utilize different blends, ranging from 10% grease and 90% petro-diesel to 90% vegetable oil and 10% petro-diesel. Some people simply use it that way, begin up and go, without pre-heating it (that makes veg-oil much thinner), or even utilize 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 really difficult and tolerant motor-- it won't like it but you most likely will not eliminate it. Otherwise, it's not smart.

To do it effectively you'll require what amounts 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 requirement for the blends.

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

Higher viscosity is not the only problem with utilizing veggie oil as fuel. Veg-oil has different chemical residential or commercial properties and combustion attributes from the petroleum diesel fuel for which diesel motor and their fuel systems are developed.

Diesel motor are high-tech makers with very exact fuel requirements, particularly the more modern, cleaner-burning diesels (see The TDI-SVO debate).

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

Otherwise using veg-oil fuel requires either a professional SVO solution or biodiesel. Mixes and blends are normally a bad compromise. But blends do have an advantage in cold weather condition.

Similar to biodiesel, some kerosene or winterised petro-diesel fuel blended with straight vegetable oil reduces the temperature level at which it begins to gel. (See Using biodiesel in winter season) More about fuel mixing and blends.