any additives for substituting antiwears (Zinc and Mg)?

[1 FMF]

have a Merc 4-cyl I/O marine engine, and Mercruiser recommends their 25w40 oil. I had the oil analyzed and it showed high levels of Zinc and Magnesium. Analysis also showed it sheared toa 30wt oil. So in substituting the Merc 25w40 marine oil with something hopefully better, my questions are

how important are Zn and Mg in oil as antiwears? if I go with some other oil and it has no Mg in it, is that bad? Does the motor need high Mg and Zn in the oil or are there other oil additives up to the task?

are there any oil additives I can add to some off the shelf oil that will increase the antiwears Mg and Zn in an oil? Would that be a good way to go?

just because Mercruiser has an oil formulated in 25w40 (it's dino by the way) with high levels of Zn and Mg, does that mean I should use a similar formulated oil? Or will other brands in the 40wt range do just as well? Even though they don't have high levels of Zn and Mg to prevent wear they are formulated to prevent wear aren't they, I guess with different additives? If that's true then it doesn't really matter what oil I go with, whether it specifically has Zn and Mg, but as long as it fits the application?

 

[darrenc]

This question really gets beat up on the boat forums. Generally speaking, these motors respond well to Heavy Duty Diesel oils such as Chevron Delo, Mobil Delvac 1300, etc. Some people prefer the straight 30 weights, I prefer the 15W-40. I happen to use Amsoil 15W-40 Heavy Duty Diesel and Marine Synthetic Oil. In your 3.0, I'd probably run the Delo or Delvac.

Your carburated 3.0 marine engine will run rich compared to an EFI or an Automobile engine. The heavy duty oils have lots of corrosion prevention additives that are well suited to deal with the marine environment and the acidic combustion by-products caused by a rich running motor. They also have excellent detgerent qualities.

The 3.0 is a very durable motor, if not underpowered somewhat. It should offer very good service with any of these oils.

 

[TurboFrog]

FYI

Advanced Lubrication Technology
Luboron

These are not PTFE-based products. They are based on Boron CLS Bond, which was developed by the Argonne National Laboratory. You will find some their test reports and articles.

[ January 27, 2003, 04:08 PM: Message edited by: TurboFrog ]

 

[MolaKule]

You might want to give consideration to either OilExtreme or Luboron if you're looking
for ZDDP alternatives.