I think the problem that has been discussed with the oem's from what i have read ,and tore down myself ,is they are leave dirtier deposits ,on the inside of the engine ,and a cleaner running engine is trying to be found here ,every logger saw engine i have torn down had real carboned up bearings that had a lot of hours on them running stihl mix ,the 32 to one may cure that washing the engine better ,i do not know ,i have not tried it yet .They protect good enough for most people though and get the job done .