What is "Marine" Gear Lube vs Gear Lube?

[hotajax]

Some bottles say "Marine" and some bottles sold out of an auto parts place don't say "marine". Whats the difference? Do you get additives that attract fish to your boat? Thanks in advance. Hot Ajax

 

[Doc Stressor]

Marine gear lube that is designed for outboard and sterndrive lower units typically contain higher levels of extreme pressure lubricants that the equivalent SAE automotive grades in order to handle the extra load. Marine lubes also contain emulsifiers that allow the lube to function reasonably well when some water is present. Conversely, some marine lubes contain demulsifiers that allow water to rapidly separate from the oil when the engine is not running. This provides some protection for the main gears during storage. But the lube should be changed ASAP after a leak is detected and the lower unit should be pressure tested to find the source of the leak.

 

[hotajax]

Doc Stressor: Thank you for that lucid and well written explanation. H. A.