Lovecraft Biofuels was a Silverlake, California operation that claimed typical diesel engines could run on vegetable oil using what is known as a "single tank" conversion. It does not heat the vegetable oil and the kit compromises filtering quality. As a result, the lifespan of vehicles with a Lovecraft system is short.
It was featured on the History Channel's show Modern Marvels: Renewable Energy Sources
References
Lovecraft Biofuels Wikipedia(Text) CC BY-SA