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 pre-owned oils.
1. Use the oil simply as it is-- generally 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 fuel;
The very first two approaches sound most convenient, however, as so often in life, it's not rather that easy.
1. Mixing it
Grease is much more thick (thicker) than either petro-diesel or biodiesel. The purpose of mixing it or blending 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 blending veg-oil with petroleum diesel or kerosene (very same as # 1 diesel) you're still utilizing fossilfuel-- cleaner than most, but still unclean enough, lots of would state. Still, for each gallon of
vegetable oil you utilize, that's one gallon of fossil-fuel saved, and that much less climate-changing carbon in the environment.
People utilize different mixes, varying from 10% grease and 90% petro-diesel to 90% vegetable oil and 10% petro-diesel. Some individuals simply utilize it that way, start up and go, without pre-heating it (which makes veg-oil much thinner), or 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 a very tough and tolerant motor-- it won't like it however you probably won't kill it. Otherwise, it's not sensible.
To do it properly you'll require what amounts 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 need for the blends.
Blends with different solvents and/or with unleaded fuel are "speculative at best", little or absolutely 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 utilizing veggie oil 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 created.
Diesel engines are state-of-the-art makers with extremely accurate fuel requirements, specifically the more contemporary, cleaner-burning diesels (see The TDI-SVO debate).
They are difficult however they'll just take so much abuse. There's no guarantee of it, however utilizing a mix of up to 20% veg-oil of good quality is stated to be safe enough for older diesels, especially in summertime.
Otherwise using veg-oil fuel needs either an expert SVO option or biodiesel. Mixes and blends are usually a bad compromise. But mixes do have a benefit in cold weather condition.
Just like biodiesel, some kerosene or winterised petro-diesel fuel blended with straight veggie oil decreases the temperature at which it starts to gel. (See Using biodiesel in winter season) More about fuel blending and blends.
