I'd also say you're changing the Amsoil prematurely if you go by the OLM. It's great stuff, yes - probably the best - but I've not put it in my '13 Cruze because it gets short-tripped a lot and I'd rather change at 5K intervals with Valvoline Synpower than want to run Ams twice as long, getting more fuel dilution, etc. in the oil, just to get my money's worth. Schaeffer's is excellent stuff, though - I use the Supreme 7000 10w30 in my truck ('85 GMC) and I'm very pleased with its performance. It's the first oil I've used in it that I feel good about lengthening my OCI (from 3,500 to 5,000) and changing the filter halfway through. Running their full syn by the OLM, no conditions you can out your engine through should push the oil's capabilities.