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...