Anyone ever use the Sierra brand High Performance Synthetic Blend Lower unit gear lube? Does it compare to the Mercury High Performance in color (blueish green). Im looking at a 5 gallon pail of it for my TRS boat. It says it is GL-5 rated, recommended for I/O applications and it surpasses the performance of the Mercury High Performance gear lube. 5 gallons of it is 157.00 at West Marine vs $200 for a 5 gallon pail of the Mercury High Performance gear lube.

Yes still sell it and use it for Service Boats asking for it. Mostly been using Mystik for the past 3 years and the price is even better yet..

Sierra also makes a full syn gear oil. The semi syn from Sierra actually works fairly well in Volvo's to and stock mercruiser apps especially Alpha apps..

I've used it for years in even in the Volvo's never a problem.

I have run Sierra lube in my Sportmasters without any issues for years also.

Used it for years no issues