I admit it...I'm a heretic. I use mobil 1 0w20 extended fuel economy oil. I will never run this car on the autobahn so I don't need the heavier 0w40 shear protection, and the lower weight oil provides slightly better mileage and power due to reduced drag at operating temp. Some folks will now likely jump all over me and burn me at the stake for saying such heretical things :-) I checked this with Blackstone Labs test engineer who does professional oil testing and they confirmed that it will never be an issue as long as I keep it under 153 mph...