I was just looking at my service manual and noticed that for the "Lowest" ambient temp. of 80 deg., 60W oil is recommended and for a lowest ambient temp. of 60 deg., straight 50W is recommended. Well in my neck of the woods we have hit that time of year where it's 65-70 deg. at 5AM and goes up from there. 90's by noon 100's by 5PM. I currently run 20W-50W and wondering about going to 60W. Does anyone use 60W?