There are at least 3 ways to run a diesel engine on biofuel utilizing vegetable oils, animal fats or both. All three are utilized with both fresh and secondhand 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 blend it with a solvent, or with gasoline;

3. Convert it to biodiesel.

The very first 2 approaches sound most convenient, but, as so typically in life, it's not quite that simple.

1. Mixing it

Grease is much more viscous (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 streams more easily through the fuel system into the combustion chamber.

If you're blending veg-oil with petroleum diesel or kerosene (like # 1 diesel) you're still using fossilfuel-- cleaner than many, however still not tidy enough, numerous would state. Still, for every gallon of

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

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

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

Higher viscosity is not the only issue with utilizing grease as fuel. Veg-oil has different chemical homes and combustion attributes from the petroleum diesel fuel for which diesel motor and their fuel systems are designed.

are high-tech machines with really exact fuel requirements, specifically the more modern, cleaner-burning diesels (see The TDI-SVO debate).

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

Otherwise using veg-oil fuel requires either a professional SVO option or biodiesel. Mixes and blends are typically a poor compromise. But blends do have a benefit in winter.

As with biodiesel, some kerosene or winterised petro-diesel fuel mixed with straight veggie oil lowers the temperature at which it starts to gel. (See Using biodiesel in winter) More about fuel mixing and blends.