I just put Amsoil ATM into a Dakota 3.9L with a 175,000 miles, 1,000 miles later it runs great and I used no flush, with conventional oil every 500-750 miles I added 2 pints make up oil so far I have added nothing.
Petty of course it is going to run good what the heck does it running good have to do with cleaning out all the left overs from years of dino oil changes? The reason for the flush is so the synthetic oil does not waste it's lubprity and solvency and other additive package charteristics cleaning out left overs from the dino oil. AN oil can try to clean or it can lubricate but they do not do both at the same time well. This is why if you do not flush the first two or three oil chages the oil turns dark very quickly and the TBN drops real fast. The dispersant package is toast early becasue it is full of junk from all dino oil changes. It has nothing to do with how well the engine runs?????If you where haveing to add 2 pints every 500-750 miles rest assured you ahve some serious deposits in that engine. No oil is going to make an engine run better or worse!!!
