Hello. I just installed GC green in my wife's '99 Accord 2.3 litre I-4 and it loves it! I also own a 2003 Accord with the 2.4 litre I-4. I've been running M1 or PP 5w-20 with no adverse effects. In fact, based upon what I've read here, 5w-20 is good stuff. However, my positive experience with the wife's car has made me curious; in fact, I'm considering switching my 2003 over to GC after the PP runs out. If your car or truck needs 5w-20 and you've used GC, what has been your experience? I am really an not concerned with a drop in gas mileage because I do not put major miles on either car, nor am I concerned with a drop in power because I typically drive gently and do not tow anything. My only concern is car longevity. Have you experienced anything positive (i.e. smoother running, really good UOA etc.), negative (funny noises, bad UOA), or has GC made no difference either way (i.e. either a good 5w-20 or GC will be fine)? Thank you for your experiences.