I have ran synthetic since 1998. Synthetic does run cleaner but engines still get dirty and get carbon on the rings. I dump in a can of sea foam in my truck whenever i get a bit of piston slap on start up. The sea foam cleans it up and i change the oil. I do this once every two years or so. Engine uses no oil. 210,000 kms on the LS 4.8 now.
Synthetic will clean to some extent but its not going to clean up a dirty or sludged up motor.
Synthetic will clean to some extent but its not going to clean up a dirty or sludged up motor.