wrong oil on oil change

[harryjt]

when i did the full service in the fall for the winter storage. I used the correct oil weight per the manual, but i failed to notice that mercruiser now wants full synthetic oil. I used mercruisers synthetic blend instead. should i drain the oil and refill it with full synthetic,or do you think the small amount of zinc in the oil for one season will be ok. I am going to go with full synthetic next fall. thanks harry i have a 2012 350 mag with the full emission system sn 2A034126

 

[tpenfield]

Re: wrong oil on oil change

Please, it will be fine . . .

I don't even use Mercruiser's oil . . .

 

[Don S]

Re: wrong oil on oil change

Everyone keep in mind that he has a brand new engine with catalytic converters. So when you say any oil will be fine, are you sure? Do you know what happens with marine catalytic converters and the systems.
The marine catalytic converters are very expensive to replace if you guess wrong or just assume it's like your non cat engines from years ago.

So be careful what you say if you don't know.

 

[Capt Ken]

Re: wrong oil on oil change

Engine oil should not be getting to the cats and if it is, he has bigger problems. The automotive industry has been using cats for decades and 99% of the vehicles use petroleum based oils. I believe if he reads the manual closer, it will say recommended. As long as it meets the required SAE rating, he's ok.

 

[Oshkosh1]

Re: wrong oil on oil change

It'll be fine.

The issue is with high ZDDP content found in diesel specific oils used by many in the boating world(Rotella, Delo et al.). Any oil(synth or dino) designed and specified for modern engines have an almost insignificant (>1%) amount due to the damage the Zn will cause to the cat.

 

[harryjt]

Re: wrong oil on oil change

Engine Oil

For optimum engine performance and maximum protection, use the following oil:
Application Recommended Oil
All MerCruiser engines Mercury MerCruiser Full-Synthetic Engine Oil, 20W-40, NMMC FC-W rated

IMPORTANT: Lubrication requirements for catalyzed engines differ from the requirements for non-catalyzed engines. Some marine-grade lubricants contain high levels of phosphorus, which can damage the catalyst system on MerCruiser engines. Although these high-phosphorus lubricants may allow acceptable engine performance, exposure over time will damage the catalyst. Catalysts damaged by lubricants containing high levels of phosphorus may not be covered by the MerCruiser Limited Warranty.

If Mercury MerCruiser Full-Synthetic, 20W-40 oils is unavailable, use the following lubricants, listed in order of recommendation. If you are servicing a catalyst engine, use these for short periods of time only.

Mercury/Quicksilver 25W-40 Synthetic Blend, NMMA FC-W-rated 4-cycle MerCruiser oil
Mercury/Quicksilver 25W-40, NMMA FC-W-rated 4-cycle MerCruiser oil
Other recognized brands of NMMA FC-W-rated 4-cycle oils
A good-grade, straight-weight detergent automotive oil according to the last row of the operating chart below.

NOTE: We do not recommend non-detergent oils, multi-viscosity oils (other than as specified), non-FC-W-rated synthetic oils, low-quality oils, or oils that contain solid additives.

This crankcase oil recommendation supersedes all previously printed crankcase oil recommendations for MerCruiser gasoline engines. The reason for this change is to include the newer engine oils that are now available in the recommendation.

Older Operation, Maintenance & Warranty manuals, Service manuals and other publications that are not regularly updated will not be revised to show this latest engine oil recommendation. Current Operation, Maintenance & Warranty manuals, Service manuals and other service publications that receive regular updates will receive this revised recommendation the next time they are updated

 

[harryjt]

Re: wrong oil on oil change

this what the manual says.. what would mercruisers definition of short period of time.

 

[tazrig]

Re: wrong oil on oil change

this what the manual says.. what would mercruisers definition of short period of time.

I spoke with a Mercruiser engineer just last week re: the exact same question. (i too have just re-powered) He told me two things that superceded all current manuals.

1) The synthetic blend is fine to use on ALL motors where full synthetic is indicated because Mercury plans to discontinue their full synthetic oil soon anyway so only the synthetic blend will be available going forward.
2) The only benefit of using the synthetic blend over the Mercury/Quicksilver 25W-40, NMMA FC-W-rated 4-cycle MerCruiser oil is the additives in the synthetic blend last longer. He told me you can go 100 hours with the synthetic blend or 50 hours with the Mercury/Quicksilver 25W-40, NMMA FC-W-rated 4-cycle MerCruiser oil and the protection would be the same.

I will probably end up using the synthetic blend and changing every 50 hours instead of 100 just to be on the safe side and to baby the motors as much as possible. Just a personal preference I guess.

 

[harryjt]

Re: wrong oil on oil change

thanks for all of the info. just save me alot of money.

 

[tpenfield]

Re: wrong oil on oil change

My apologies to the OP for an improper response on this thread :facepalm: