Quote Originally Posted by niky View Post
The impurities and particulates in waste vegetable oil make it unsuitable for use in CRDi engines, even if you filter it.

It might be possible to strain the oil with a 1-micron filter, but even then, there's no assurance that the contaminants and/or water content will not damage your pump and/or injectors.

Best to convert it to Biodiesel, but I've heard that this may have an unwanted effect on the valves of ordinary diesel engines if you use 100% Biodiesel.
Hence the advise to use a 50/50 blend of bio-diesel with regular diesel.