Ive heard of people running their vehicles on unrefined fryer grease, is this biodiesel?
Although biodiesel can be made from fryer grease, the grease alone as it comes out of the fryer is not biodiesel. While diesel engines can burn straight vegetable oil (or SVO as it is commonly called), there are many limitations that prevent it from being used as a fuel replacement. SVO is much thicker than refined fuel, and can only be used as diesel fuel when it is pre-heated prior to being fed to the engine. Simple systems exist that use heat from the cooling system to heat the incoming fuel prior to injection into the engine. But in this case, the engine must be started up and shut down on regular diesel fuel or biodiesel, then switched to SVO while the engine is running. For this reason, SVO isnt as user-friendly as biodiesel, and isnt recommended for most people.
