I can highly recomend the old style little metal cans of Toyota's Injector cleaner. It is seriously concentrated and must be made up of close to 100% Amines and Butyl Cellulose XXXXXXX.... It has the viscosity of sligly warmed syrup or honey and has a yellow color. While I am sure their are some petroleme distilates in it their must not be many. I could not smell any petroleme distillates in it over the strong smell of amines! I added it to a half tank of gas intending to fill the tank. Needless to say I never filled the tank and am now down to a 1/4 of a tank. I can already fell a marked improvment in idle and smoothnes of the engine.