Do you think Saturn would kill my warranty if I wanted to use a synthetic or part synthetic oil like Mobil 1 or Clean 7500? I have the 2005 ION QC (not redline) and the manual is pretty explicit on regular oil, but I want to have this car last a good long time and the Clean 7500 is less than a quart. Also I like having the dealership do the maintenance until the warranty is expired, so since they do not stock Clean 7500 I would have to provide it. Or is Mobil 1 that much better and worth the extra money?