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

1. Use the oil simply as it is-- typically called SVO fuel (straight vegetable oil);

2. Mix it with kerosene (paraffin) or petroleum diesel fuel, or with biodiesel, or blend it with a solvent, or with gas;

3. Convert it to biodiesel.

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

1. Mixing it

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

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

People utilize various blends, varying from 10% grease and 90% petro-diesel to 90% grease and 10% petro-diesel. Some individuals simply utilize it that way, start up and go, without pre-heating it (that makes veg-oil much thinner), or perhaps use pure vegetable oil 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 tough and tolerant motor-- it will not like it however you most likely won't kill it. Otherwise, it's not smart.

To do it appropriately you'll require what totals up 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 requirement for the mixes.

Blends with different solvents and/or with unleaded gasoline are "speculative at best", little or nothing is learnt about their results on the combustion qualities of the fuel or their long-lasting effects on the engine.

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

Diesel engines are high-tech machines with very accurate fuel requirements, specifically the more contemporary, cleaner-burning diesels (see The TDI-SVO controversy).

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

Otherwise using veg-oil fuel requires either a professional SVO solution or biodiesel. Mixes and blends are generally a bad compromise. But mixes do have an advantage in winter.

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