The M1 0w40 did the same as the 10w30 did today. I was hard on the gas today and it ate 1qt of oil in a 100 mi. It only used a 1/4 qt on over 1000 mi of mostly 70+ mph driving. I didn't rev the motor hard in that 1000 mi. On the 70 mi drive home it used no oil. When I ran the Rotella 15w40 in the mts with the motor working very hard with a full load it never used that much oil at one time. As winter is comming I don't want to use 15w40 as it gets -30 out. I can't find Cheveron oil in WI, Cary what do you suggest?