I'm not trying to be a Debbie Downer but can anyone show me incontravertable proof of an engine's internals that were "cleaned up" using only an HDEO or synth? I just see all these people posting things like "Just use xxxx type of oil and the "detergency" will clean things right up." Yet, I've never seen anyone come back and say "Yeah, look at these before after photos! BrandX cleaned it right up after x amount of oil changes." Arx is the only thing I have seen come close and it itself seems to need all the planets aligned to work sometimes. Now, I don't want to turn philosophical here and turn the thread into a debate over "What is a CLEAN engine?" or anything else. I just want to see if anyone has documented experience with oils cleaning a horribly dirty engine. No engines that have been run since day 1 with synth just to show how clean they are. That's not the point. Also, please don't post pics bragging about the 20k of synth cleaning your engine to the point where all it needed as a simple scrub down with diesel fuel inside or an easy hot tanking to look brand new.