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

1. Use the oil simply as it is-- generally called SVO fuel (straight veggie 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 very first two methods sound most convenient, however, as so typically in life, it's not quite that simple.

1. Mixing it

Grease is a lot more thick (thicker) than either petro-diesel or biodiesel. The purpose of blending it or blending it with other fuels is to decrease the viscosity to make it thinner so that it streams more freely 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 utilizing fossilfuel-- cleaner than many, however still unclean enough, lots of would state. Still, for each gallon of

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

People utilize different mixes, ranging from 10% grease and 90% petro-diesel to 90% grease and 10% petro-diesel. Some individuals simply use it that way, start up and go, without pre-heating it (which makes veg-oil much thinner), or perhaps use pure grease without pre-heating it, which would make it much thinner.

You may get away with it with an older Mercedes 5-cylinder IDI diesel, which is a really tough and tolerant motor-- it will not like it but you most likely will not kill it. Otherwise, it's not wise.

To do it correctly 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 need for the mixes.

Blends with different solvents and/or with unleaded fuel are "speculative at best", little or nothing is understood about their impacts 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 various 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 state-of-the-art machines with really accurate fuel requirements, specifically the more modern-day, cleaner-burning diesels (see The TDI-SVO debate).

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

Otherwise using veg-oil fuel needs either a professional SVO service or biodiesel. Mixes and blends are normally a bad compromise. But blends do have a benefit in winter.

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