Well on the other hand though, there are distributors who have recommended using synthetics. I know I said distributors but the engine manufacturer evidently themselves have agreed to this method or else they couldn't make that recommendation or could they? Atleast this distributor has.I believe they can make that kind of recommendation because 90% of their motors are serviced in house instead of sending them back to the manufacturer.I believe the manufacturer has total confidence in the distrubutors ability to diagnose, represent,and service their motors without questions , simply because of the distributors knowledge on their egines.