There seems to be many people who use Shell Rotella T 15w40 oil in many different applications ranging from lawnmowers, motorcycles, to daily drivers. It seems to be a fine oil, but on another forum a user posted, "Rotella is a very good oil for any 4-stroke gasoline engine." Is that true? Even when my daily driver (Ford Escape V6) calls for 5w20? What would be the pros/cons of switching to Shell Rotella T 15w40?