Last Saturday, I happened to be at an AA store and I noticed they were carrying Castrol Edge 0w40. Technically, none of my cars use 0w40, but I have noticed that the Mobil website recommends 0w40 for my 95' Mercedes E320 (Manufacturer specs. call for either 5w40 or 10w40)even though it has 118500 miles on it. Seeing that it's BOGO right now, should I try it? I just recently bought 36 quarts of Valvoline Nextgen Maxlife 10w40 and 15 quarts of Peak conventional 10w40, so I really won't need any oil for the car for a good while, but I do keep wondering how 0w40 would be compared to 10w40.