if ur runnin atf in ur engine, how much are u puttin, surely, ur not replacing oil with tranny fluid
I usually put a 1/2 quart in my engine 500 miles before I change the oil, replacing the oil completly would not be a good thing. FFC is correct ATF deep cleans and still comes with the lubricating properties so it won't harm the internal components. I wouldn't doubt that those expensive additives for cleaning sludge in your engine are for the most part ATF.
