Ok heres one for you. My wife has a 2000 Trooper with the 3.5L engine and auto transmission. We bought the car with 10k miles on it, it now has 56k. The engine uses about 1 qt per 3000-3500 miles. I originally used M1 10w-30 then M1 5w-30. I switched to Valvoline All Climate 5w-30 thinking the M1 was causing it to go "somewhere". The motor runs fine, just the usual valve train noise these motors make. What would be the best oil to run in these motors, and where would this oil be going? (no smoke or drips at all)