in my 98 chevy truck with the 5.7L. I have gone about 500 miles since putting in the Auto-RX with the 10W-30 Mobil drive clean and new filter. I checked the oil today and its still looks clean, not black at all. I'm going to go 800 miles before changing oil & filter. Does the fact that my oil is still clean, mean that my engine was pretty clean to begin with or that I need to run this application quite a bit longer than 800 miles? I've ran Mobil 1 for the last 35,000 miles so I don't know if that has something to do with it. My tapping noise in the engine seems to have gone away so thats good. Thanks for any input.
Wayne
Wayne