I have used Mobil-1 in all my cars for many years, and I had an Chevy Astro minivan that went to 250k on the original engine with 10k oil and filter changes from 30k on when I switched it to Mobil-1. I had to have the head gasket replaced at 150k and asked the mechanic to let me know what the cylinder head looked like. The engine was very clean and gave me no trouble, and I donated it when it got to 250k (the rest of the car was wearing out).

I now put all my cars on a 10k oil and filter change interval with Mobil-1 when they go out of warranty, and I have never had any oil issues at all. I plan to follow the FSS recommendation on the Crossfire. Personally, I think more frequent intervals for normal driving service cars is wasteful.