Yesterday went on an 80 mile ride in the heat. West coast has a heat wave. Temp is running 200 to 210 climbing the long steep grades at 20-25mph. Not a lot of good air flow going through the radiator. Fan can only do so much. If anyone is running the 20w50 oil let me know what brand y'all are running. Or maybe I'm just run 5w50 year around. The 10w40 just not made for this high heat desert.