There are at least three methods to run a diesel motor on biofuel utilizing vegetable oils, animal fats or both. All three are used with both fresh and pre-owned 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 fuel;

3. Convert it to biodiesel.

The first 2 methods sound simplest, however, as so frequently in life, it's not quite that easy.

1. Mixing it

Vegetable oil 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 streams 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 many, but still unclean enough, many would say. Still, for every gallon of

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

People use different blends, ranging from 10% grease and 90% petro-diesel to 90% veggie oil and 10% petro-diesel. Some individuals just utilize it that method, launch and go, without pre-heating it (which makes veg-oil much thinner), and even utilize 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 an extremely tough and tolerant motor-- it will not like it however you most likely won't kill it. Otherwise, it's not sensible.

To do it correctly you'll require what totals up to an SVO system with fuel pre-heating anyway, preferably using pure petro-diesel or biodiesel for starts and stops. (See next.) In which case there's no need for the mixes.

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

Higher viscosity is not the only problem with utilizing veggie oil as fuel. Veg-oil has various chemical properties and combustion qualities from the petroleum diesel fuel for which diesel engines and their fuel systems are developed.

Diesel motor are state-of-the-art devices with very precise fuel requirements, especially the more modern, cleaner-burning diesels (see The TDI-SVO controversy).

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

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

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