dsberman94
Well-known member
Is there any benefit to switching back to 15-40 for summer? Truck has had 5-40 in it since new is what the PO told me. They ran mobile1 5-40 but I ran rotella. If I go 5-40 I'm thinking of changing to maybe delo if they have a good price on it. If it's way expensive I'll stick with rotella. So any benefits of switching to 15-40 for warm weather then back to 5-40 for the cold weather or just run 549 year round.