premium or hi performance lower unit oil

[dave37]

Winterized my 50 hp 1973 4 cylinder 2 stroke Merc on the weekend, on filling the lower unit I realized the clerk had sold me "Premium" Mercury lower unit gear oil. I have been using the blue colored "Hi performance" Merc oil. Can I safely use the two mixed together (I had pumped in half of my old bottle of Hi Performance and Half of the premium), and which would be preferred, the premium or the hi perf??

Thanks!

 

[Barnacle_Bill]

Re: premium or hi performance lower unit oil

Merc parts man told me the high performance was for the bigger motors (150+). I can't see where mixing them would be any problem.

 

[Texasmark]

Re: premium or hi performance lower unit oil

Me neither. All that means is that the Prem has more or a different type of additive to increase the surface tension required to keep the oil in place with the higher component pressures of the higher hp engines.

I mix syn and regular all the time and with respect to oils, any oil, I have never in my life seen an oil, nor grease for that matter, separate out from incompatability. And even if it did, so what? As soon as you turn her on it will get stirred up again and both of them are lubes, and both are touching the parts.

Mark

 

[LubeDude]

Re: premium or hi performance lower unit oil

Your fine and have recieved good advise.

I have only seen incompatability issues with different greases, I always completly clean as best I can all the grease out before relubing. The incompatability issue came with my sons boat trailer bearings, he pumped in some red grease of some kind and it was gelled with the other grease when we repacked them this spring. I have no idea what brands they were.