Mercury no longer has high performance plus gear oil now they call it just high performance and changed formulas made it more of a blend??? Cheaper to make??? Kind of wary of this probably switch to another product running 120 plus any suggestions for a better oil

It really does not matter what you run as long as you change it often and have the drive rebuilt at the first sign of tiny metal slivers. Dust that turns into mush between your fingers is ok but the smallest shavings is bad news.

Whatever fluid makes you feel warm and fuzzy inside, but the new merc fluid is ok

other options

Amsoil severe gear 75/90 or 75/110 or 75/140
Mystik
Bravo Shop Neo Oil

I think the Amsoil 75/110 provides better shock protection. Never had luck with the 90 weight.

Getting ready to try Mystic - heard good things about it.

I thought about starting a new thread, but my question seems relevant. I started using Amsoil Severe Gear last year at start of season. Changed at 25 hours about half way through season. Within about 5 hours after first lube change (2nd use of Severe Gear), I started to develop a lazy drive.

Coincidence??? Or cone clutch going bad? Eddie Young adjusted cables when he had boat, so I believe that section is correct.

I've went back to Merc for this season. Only time will tell.

The new Mercury HP gear case oil is "Mercury Racing Gear Oil", part number 92-8M0078016 for 5 gallons. The O/B 300 XS guys are using it. They are terribly hard on gear cases!

What is the downside to running the 140 weight? Why not just always run the greater weight oil?