GL-4 for Yamaha Lower Unit - Borate vs Sulfur additive Pack?

[JHZR2]

We have a new to us 2020 Yamaha F20 outboard and it needs service.

The spec is a GL-4 lube.

I realized the Havoline 90wt we have is GL-5 and not much else.

No good for use here.

Looked at the auto parts store, because I was picking up a filter element, and some of the gear oils are GL5 and GL4 rated.

That got me thinking… Because my FIL owns a Chevron distributorship, their Delo ESI may be on hand and available cheap.

https://cglapps.chevron.com/msdspds/PDSDetailPage.aspx?docDataId=76979&docFormat=PDF

It’s interesting stuff. It says that it is suitable for GL-4, and details how its borate chemistry gives 3-5x more antiwear film thickness than a sulfur/phosphorous additive package.

Any thoughts on the suitability of something like this for an outboard?

Would borate with a thicker film be better in marine applications? Specifically saltwater?

I’m not sure the Yamaha lube is anything overly special. But it is always an option too…

Thanks!

 

[PontiacHO]

Why not Yamalube? Can’t go wrong there. Order through Amazon and delivered to your front door. If not that then Quicksilver Marine gear lube. Both have additives that work if there is water intrusion.

 

[JHZR2]

Why not Yamalube? Can’t go wrong there. Order through Amazon and delivered to your front door. If not that then Quicksilver Marine gear lube. Both have additives that work if there is water intrusion.

Nothing wrong with the Yamaha stuff. It’s just a matter of location, time, etc. This boat is not stateside.

And can access Chevron stuff easily.

Also the different add pack is interesting regardless.

 

[Overfill]

No good for use here.

Why

 

[userfriendly]

Delo ESI gets my vote.
Why?
Because I’ve used it before in various applications including motorcycle and automotive transmissions and old transfer cases with good results.

 

[4WD]

Marine gear oil contains more emulsifiers to handle water intrusions whilst still protecting gears …
This can also prevent damage from freezing temps in storage …

 

[Rand]

my vote:

 

[Donald]

You are talking about one cup of the lubricant. Get the Yamaha.

 

[repairman54]

I use the Quicksilver lube. As said use the proper marine gear lube.