I would stick with the 10W60. The 8 cylinder model calls for 5W40. I checked with the dealer and they confirmed 10W60 for the 6 cylinder. They had no clue as to why. Regardless of logic I'm using it for fear that other weight would give them the excuse for not honoring warranty work. I order Castrol Edge Supercar from Amazon at $130/case of 12 quarts.