i got onboard with Amsoil as well. 3rd oil change. only run it for 5-6k thought. i went with 9k and send for UOA and it came back with 50% oil life, i didnt wana risk it. so i do it at that, for ppl with regular cars (focus and all those non performance cars i guess 20-25 would be fine), but thats just what i think, it costs me about $45 per oil change though with discount but i like best for my car
Always better to err on the side of caution if your needs are not typical. Me, I just run to work and back and only put on like 16,000 km per year..not much. I have not done an oil analysis yet..it would be cool to do so. Great oil is always the cheapest insurance for your motor, no question.
