Conventional 4 stroke oil vs. Marine

[Jeepster_nut]

What are the major differences between Marine and regular 4 stroke oil? I have a PWC that calls for 10w-30 but the manual just states that I should use 4 stroke detergent oil with the API rating of SF, SJ, etc.

I have been going out of my way to get the Mercury Quicksilver, but am considering switching to regular oil if there aren't any negatives.

 

[MolaKule]

What engine and setup?

Marine oils shold have more rust inhibitor and a bit more emulsifier.

You should be able to use just about any oil with the proper ratings but you might want to have the oil analyzed for moisture content and change it more often.

 

[Jeepster_nut]

Its a 2008 FX HO yamaha PWC. 4 cylinder, 4 stroke, 5 valves per cylinder. 160 HP @ 10,300 RPM's. It calls for 10w-30 but Yamaha now recomends 10w-40 due to increased consumption issues with the 10w-30 as engine hours increase. I have considered West Marine's store brand 10w-40 for outboards. Has anyone else used West Marine's oil and does anyone know who makes it?

 

[willix]

In car with a 5.7 chev as an example, its easy cruising at 50 mph the engine maybe needs 35-45 horsepower to drive that car down the road. That 5.7 chev engine in a boat will need closer to 200HP to maintain 50 mph. The boat motor is working with max load to for the effort it needs to drag it along at any speed over all rpm ranges say above 1000 rpm and to get the hull to plane uses a lot of power. They work very hard.

 

[Jeepster_nut]

Yea, from what I have been reading I think its best to stick to an FC-W rated oil. West Marine's store brand 10w-40 made the NMMA FC-W list, so I will end up using that. It is for 4 stroke outboards but it should be fine for my PWC as it is water cooled also.

http://www.nmma.org/certification/programs/oils/fc-w.asp

 

[Bluestream]

Originally Posted By: MolaKule
What engine and setup?

Marine oils shold have more rust inhibitor and a bit more emulsifier.

You should be able to use just about any oil with the proper ratings but you might want to have the oil analyzed for moisture content and change it more often.



What exactly is added to an oil as a "rust inhibitor"?

 

[Badlees]

Originally Posted By: Bluestream
Originally Posted By: MolaKule
What engine and setup?

Marine oils shold have more rust inhibitor and a bit more emulsifier.

You should be able to use just about any oil with the proper ratings but you might want to have the oil analyzed for moisture content and change it more often.



What exactly is added to an oil as a "rust inhibitor"?


Sodium???

 

[Steve S]

The marine companies I have been to use HDEO in their gasoline and high speed diesel engines.You don't need any other kind of oil. That being said Marine engines work hard so frequent oil changes are good.

 

[MolaKule]

Quote:
What exactly is added to an oil as a "rust inhibitor"?


Here is some data in the public domain:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=530321#Post530321

right now, we use Proprietary additives for rust inhibition and protection.

 

[Bror Jace]

"right now, we use Proprietary additives ..."

We??? Did I miss something? Are you back in business?

 

[oilboy123]

Originally Posted By: Bror Jace
"right now, we use Proprietary additives ..."

We??? Did I miss something? Are you back in business?

That's what I was wondering.......

 

[Fordiesel69]

IF ambient temps are high, ditch the multigrade and goto a mono grade SAE 30WT. I mean 70's and above. If your temps get in the 50's, it may be better to use 10w-30 in a diesel oil. Skip the high price mercruiser oils.

Trick with marine is more oil changes, more often. The engines get so hot any moisture will boil off, but fuel dillution and breakdown will not.