SVO vs Biodiesel

SVO use, by contrast to biodiesel, requires a heated fuel system, and most often a second fuel tank and filter, to be able to start the engine, move the SVO from tank, through fuel lines, filter, injection pump and injectors, as well as to accomplish the best atomization within the engine (lowest emissions, and least likely to cause harm to the engine).

The objective is to heat the vegetable oil to approx. 70C at the point of injection. It is not necessary, or even desirable, to try and heat the SVO to this high temperature in the entire fuel system, only at the point of injection. So, SVO can be heated "progressively", along it's path from the tank to engine, and it is most effective to use a combination of coolant-based heaters at the tank, at the filter, etc. and then use an electric heater just before the injection pump.

In many cases, in warm and moderate climates, good new or lightly used cooking oils, it is not necessary to use a tank heater. However, with thicker "grease", that is, vegetable oil that has become more "hydrogenated" by its time in a fryer at high temperatures, and this in combination with cooler ambient (outdoor) temperatures, tank heaters can certainly be desirable. As an example, a system could function perfectly in Greece, or other warm/hot climates, year round, even on used cooking oil, without a tank heater and without a "heated path" (heating of the SVO fuel line by running coolant lines from the engine along its path to the tank)