This is a me problem and not the fuel. When all I could get {on sale
} was the WC 15/16 the 16% oil did give me pause. I added two ounces of Klotz just because. Now even the new Powermaster is only 17% oil. I'm still using my 15%-18% fuel and haven't decided if I will add a bit of oil or not. I know I don't need to with the blends we have today but my mind is still in old school land? My engines are old school too and the instructions call for 20% oil, I never gave them more then 18% though. It's just that 16% and 17% strikes me as a bit low. I know, get over it and get with the times!!!