What is the difference in Marine oil vs other oils?

[Doc]

First year with current boat and previous owner told me he changed oil and used Mercruiser oil aka Quicksilver Marine oil.
So I bought a gallon sized containter and it cost more than Mobil One full Synthetic that I have been using in all previous boats.

I did buy it from a boat dealer / repair shop, since on one else had any in stock.

Is there an advantage to using spcific marine oil instead of a full synthetic of the same weight?

 

[Phillbo]

Not sure if their is a difference but I've used quicksilver in every boat i've owned and never had an oil related failure. I do a Blackstone oil analysis every 3-4 years and always get good results.

I'm sure many people use mobil one with good results as well. I use it in my tow vehicles.

 

[Doc]

Same here with Quicksilver and Mobil One.
Years ago I had a Force 235 Baja. Awesome boat. 7.4 / 454 / 330 hp. I ran Quicksilver for 6 years or so with it then tried Mobil One. Operating temp dropped from 163 to 156. Lower temp seemed good all the way around so I stayed with Mobil One for all my boats since then. I've also used Blackstone with good results. So just got to wondering if there is a difference in the Marine oils that I am not aware of.
Thanks for your response Philibro

 

[Paulswagelock]

The additive pack is the difference. If an oil is NMMA fc-w certified, it has to meet or exceed the criteria in the spec. The main parts are hths value for sheer stability, foaming prevention, and rust prevention. Honestly, many oils would meet or exceed that spec, but are not interested in the time/cost to get the certification for the small amount of oil sold compared to the automotive market.

 

[Doc]

The additive pack is the difference. If an oil is NMMA fc-w certified, it has to meet or exceed the criteria in the spec. The main parts are hths value for sheer stability, foaming prevention, and rust prevention. Honestly, many oils would meet or exceed that spec, but are not interested in the time/cost to get the certification for the small amount of oil sold compared to the automotive market.

Thanks Paul. Good info.

 

[Iggy]

I used Mobil One for 9 years and than sold the boat. I talked to the new owner off and on and the engines are still doing great. So far so good!!!

Now using Mobil One in my diesel engine.

 

[Doc]

I 'read' that diesels need to get up to a certain temp to operate efficiently and synthetic oil causes them to operate at a cooler temp.
For that reason I use Rotella or an oil that says it's made for diesel in my tractor and kubota RTV side by side.