Royal Purple Max Gear 75-90 synthetic.....

Amsoil severe gear w/ lucas additive.

Amsoil Marine, is there anything else? I've done a lot of research, I have yet to find anything better. I like the product so much I became a dealer.

Merc high perf. gear lube, it came in it ...it stays in it !

Is the Mercury "Hi-performance" gear lube synthetic?

Maybe this link will help, it states that there are synthetic additives.
http://www.mercurymarine.com/parts-a...nce-gear-lube/

Merc is a blend, switched to Amsoil severe gear and much better results over the three boats in my immediate group. Way less discoloration, no shavings what so ever. ..................................Rjr............. ..............................

I am hearing good things about Amsoil severe gear, I am wondering if I should make the switch from the Royal Purple??

a mix of amsoil severe and lucas...i use lucas in everything

royal purple. Looks brand new at the end of every summer (less then 40hrs)

Have also heard of people running 100% lucas. (big boats, with twin high hp engines) Would be interested to hear peoples thoughts on that