I have been adding ATF to oil for over twenty years with nothing but good results (cleaner engine internally) I agree that you should not do it to engines that have been running non-detergent oil. I also stated that I let it idle for 10 minutes before I drain. I do not nor do I recommend driving with this additive. ATF is 10 weight oil with a highly detergent additive. I use it every 3rd oil change if the oil is looking black and dirty before I change (3000) miles. Since I do not buy new vehicles I see this gradualy cleaning up engines that have not been maintained correctly. This really only applies to modern cars. I do not advocate this in old vehicles. Just what I do. I'm comfortable, it works for me!
