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

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

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 very first 2 approaches sound simplest, however, as so typically in life, it's not quite that easy.

1. Mixing it

Grease is much more thick (thicker) than either petro-diesel or biodiesel. The function of blending it or mixing it with other fuels is to reduce the viscosity to make it thinner so that it flows more freely through the fuel system into the combustion chamber.

If you're blending veg-oil with petroleum diesel or kerosene (very same as # 1 diesel) you're still utilizing fossilfuel-- cleaner than the majority of, but still not tidy enough, numerous 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 environment.

People utilize different mixes, ranging from 10% veggie oil and 90% petro-diesel to 90% vegetable oil and 10% petro-diesel. Some people just utilize it that way, begin up and go, without pre-heating it (that makes veg-oil much thinner), and 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 an extremely difficult and tolerant motor-- it won't like it however you most likely will not eliminate it. Otherwise, it's not sensible.

To do it properly you'll need what totals up to an SVO system with fuel pre-heating anyway, 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 numerous solvents and/or with unleaded fuel are "experimental at best", little or nothing is understood about their impacts on the combustion attributes of the fuel or their long-term results on the engine.

Higher viscosity is not the only issue with using vegetable oil as fuel. Veg-oil has different chemical properties and combustion characteristics from the petroleum diesel fuel for which diesel motor and their fuel systems are designed.

Diesel motor are high-tech machines with very accurate fuel requirements, especially the more modern-day, cleaner-burning diesels (see The TDI-SVO debate).

They're tough however they'll only take so much abuse. There's no guarantee of it, but using a blend of approximately 20% veg-oil of excellent quality is said to be safe enough for older diesels, especially in summer.

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

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