We prefer the Edge 10W-40 due to its far superior film strength when compared to the 5W or 0W versions. The Edge 0W-40 is better than the Mobil 1 product in many ways, but that said I am not a fan of 0W anything. 0W-X oils start from a thinner base stock and use a lot of additives to get the hot weight. These thinner base stocks offer less film strength in use and are the weight that the oil will try to revert to as the additives fail with time. So rather than use 0W-40 Edge, I would give serious consideration to the 5W-40 or even 10W-40 Edge products over the 0W-40.

Hi JFP in PA, was reading through your oil recommendations for boxster, and it seems you highly recommend Castrol Edge 10W40. What are your thoughts on the Castrol Edge 0W40 A3B4? Does it thin quickly (a la Mobil 0W40)?