I've got a 2006 Ford Escape with the 3.0 EcoBoost engine. It weeps oil, as a lot of them do. I've been using Castrol 5W-20 High Mileage synthetic blend, and don't have to add oil between oil changes, but the stain on the driveway annoys me. I see 5W-20 conventional oil at Meijer and Farm and...