I use a high grade of motor oil... I have always liked Valvoline. But Quaker State, Pennzoil and other top brands are probably equally good. Stay away from the bargain brands. Quality lubrication is essential to your engine's longevity. In general you want it to look clear and green on the oil dipstick... when it starts getting dark, it's time to change it, and when it gets black it's way overdu