I hear alot about guys adding 2 cycle oil to help clean the diesel fuel and for mpgs. Has anybody done this and has it let to any problems wih injectors or anything else? Also what was the results as far as smotther running engine and mpgs increasing? What kind of oil(be precise please) and how much do you add? I have a 40 gallon tank....tell me what yall think and how it has hurt or helped you!!!!!!