Synthetic oils suck for a motor in my opinion!! Bearing failure for me had a lot to do with the oil. Besides how much will you gain from 7 quarts of $8.00 oil? I like the old Kendall oil.. Glad its back.. If you have any questions about the old Kendall just call Stanton and ask about the oil clean up and how long it took when I dropped a rod there.. My trailer floor is still slick!!