I wouldn't run straight 50W for anything but racing, but that's just my opinion. In Valvoline's Racing Oil I'd go with their VR1 10W30 - Amazon.com: Valvoline (VV205-6PK) VR1 SAE 10W-30 Racing Motor Oil - 1 Quart Bottle, (Case of 6): Automotive You get the viscosity of 10W on startup, when the oil is cold for good flow and lubrication, and as it warms the viscosity becomes 30W.