Don't try this at home. Just a small piece of dirt can damage your fuel injectors and fuel pump. What was not tested here is long term use of cooking oil. Diesel fuel you buy at the pump as many different additives in it. If your going to play around with your generator it would be a good idea to get some better fuel filters, extra fuel injector and fuel pump. What is also not mentioned here is the viscosity of the fuel. Cooking oil will gel faster in colder weather. Many people preheat them first. Also a car can adjust the timing and make up for the different flash points of various fuels. Your generator can not.