My '12 CRV has 275K miles and I have done every interval from 5K to almost 10K, and used every weight between 0W20 and 10W30, HM and regular, and all kinds of additives. I have used Castrol Edge, Castrol GTX blend, GTX FS, M1 AFE/EP, PP, PUP, and I think I used Amsoil once or twice. 80%...