Gear box oil

[popeyethesailor]

Hi does any one know why quicksilver say don't mix there 'premium gear lube'
With there
'high performance gear lube'

I know one if for lower HP outboards


I had to do a oil change today with the 'high performance' as it was all I could get hold of,
I can't see a problem with it unless I am missing something 👀

Thanks in advance

[beamishken]

One is synthetic one is mineral oil green is synthetic clear/ golden brown is mineral just use what's already in as they don't mix
Take the plug out & check the colour to see what's fitted to your box

[Jon Tallis]

As Beamishken says, one is synthetic, one mineral.
If you can't get the 'normal' stuff I'd assume the high performance oil is better, but won't like being mixed with 'normal'

If you drained the box really well, gave it a fill of 'high performance', drained it and filled it again, I'm sure you'd be fine.

[spartacus]

The high performance synthetic brand is for sterndrives (SAE 90) or outboards above 75hp, and the mineral oil brand is for outboards below 75hp (SAE 80-90). Did the same thing myself, but as long as it's drained well you'll be fine.
Outboard Lower Unit | Quicksilver Products

[uncle al]

Before I retired I always used the quicksilver highperformance gear oil, in every OBM regardless of what HP.

[popeyethesailor]

Thanks for that I should have guessed one was synth 🙈

It's all coming out again anyway now the lower unit has a oil leak think it's the one on the prop shaft hopefully it will be a easy change on a 3.5 tohatsu