Best lower unit oil?

Hi Everyone.
Looking for some input on what you think is the BEST lower unit oil options.

Price and how well it holds up against moisture.

I've had good luck with the quicksilver full sythetic.

Also, marine grade oils supposedly are supposed to have properties to make them hold up better to moisture. Do you think this is true or is it just dye and it doesn't look so bad?

I've used regular automotive gear oil and it seems like it didn't take much to turn that stuff into milk.

I havn't tried full synthetic automotive gear oil but have some left over 85-140 and 85-90 Royal purple(full sythetic, purple, about $15 a quart) from my truck differentel oil change I'm fixing on trying.

Royal P isn't really the alternitve I'm looking for...it is higher than the marine stuff....but maybe it will say how automotive sythetic holds up to the moisture.

Re: Best lower unit oil?

Its water ingress that turns gear oil to milk. Dont waste money on expensive oils spend it wisely on new seals. Use an outboard gear oil to API GL5 spec. Outboard oils they tell us contain extra inhibitors to protect against th effects of water.
Normally they are in the SAE 80-90 range