I have heard from different people that mercury quicksilver 2 cyl. Oil is the best out there. Even on non-mercury motors. Can anyone tell me why this is or is there any truth to it. Its very expensive but are there advantages to using it. I run penzoil xlf with both my boat without issues. I sort of look at like most lower unit grease /oil---if you look at the bottle of most lwr unit specs are the same as auto rear ends 80w90. Specs on bottle are the same except for the ones that have synthectic additives. ?????????????????