check your owners manual for engine oil specs. then purchase an oil that meets those specs (lable on back of container will have the specs) I use shell rottella T full synthetic(they just came out with the "low sulphur" engine oils), Amsoil has good stuff, valvoline blue etc, just be sure they meet the specs as required and stated in the owners manual, keep track of oil changes including receipts, this will statisfy the dealer.
PS. you'll get all kinds of opinions on which oil is best, its up to you which you decide on but just be sure it meets the specs.
Last edited by SpLaT; 12-10-2008 at 12:12 AM.