Any oil you like will work. I have run Mobil 1 full synthetic to diesel oil in mine. For a total stock engine, 10 w 30, up 20 w 50 will work. 10 w 40 is probably the best all around weather oil. The synthetic did drip out the rear main more then standard oil, that and the cost made me switch. The 5w20 I run now isn't much better for leaking, but the cost is cheaper.
