what type of oil do you use

[finer things]

my question is this what kind of oil should I use in my 1987 5.7 mercruiser I know they recomend use quicksilver 25w40 but is it really necessary and if not what kind woud you recommend

 

[finer things]

can I use automotive oil in boat

can I use automotive oil in boat

I was just wondering if I should use mercruiser oil in my 1987 mercruiser 5.7 260 horse or if it really matters

 

[Fishermark]

Re: can I use automotive oil in boat

Re: can I use automotive oil in boat

Everyone will have their own opinion... I personally like the Mercruiser High Performance - the "green stuff." (You are talking about the gear oil in the outdrive - right?)

 

[Aloysius]

Re: what type of oil do you use

Don't run 20w-50..it will wear the distributor/oil pump drive gear excessively. Personally, I run 15w-40 oil with zinc in it for the flat tappets.

 

[fraannk]

Re: what type of oil do you use

The best thing about these forums is the fact that almost any question has already been asked. There is no need to wait for a response. Just do a search in this forum and you will come up with the numerous threads where this exact question has been asked. By the way, there are probably more opinions about this than registered users.

 

[Fishermark]

Re: what type of oil do you use

Here ya go - if you want to use what is recommended, the quote from Mercury Marine should help. If you want to use something else, go ahead - someone will back you up!!

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.

1. Mercury/Quicksilver 25W-40 Synthetic Blend, NMMA FC-W-rated 4-cycle MerCruiser oil
2. Mercury/Quicksilver 25W-40, NMMA FC-W-rated 4-cycle MerCruiser oil
3. Other recognized brands of NMMA FC-W-rated 4-cycle oils
4. 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.

 

[sethjon]

Re: what type of oil do you use

my question is this what kind of oil should I use in my 1987 5.7 mercruiser I know they recomend use quicksilver 25w40 but is it really necessary and if not what kind woud you recommend

Amajor brand 10/40 is great!

 

[sethjon]

Re: can I use automotive oil in boat

Re: can I use automotive oil in boat

I was just wondering if I should use mercruiser oil in my 1987 mercruiser outdrive or if it really matters

Definitely. Major brand 10/40

 

[finer things]

Re: can I use automotive oil in boat

Re: can I use automotive oil in boat

no not gear oil engine oil

 

[Bifflefan]

Re: can I use automotive oil in boat

Re: can I use automotive oil in boat

In the outdrive, yes it makes a big difference. Use only outdrive oil.
Regular 90wt will foam up and outdrive oil wont.
If your trying to save a buck, this is not the place to do it.

 

[cr2k]

Re: can I use automotive oil in boat

Re: can I use automotive oil in boat

You can use an 85-140 gear oil in the drive. Better to use a synthetic blend.

Never heard of gear oil foaming up. What's the difference between being in a water cooled enclosure and a differential of transfer case?

 

[parasail]

Re: can I use automotive oil in boat

Re: can I use automotive oil in boat

Marine designated engine oil has more rust inhibitors in it than automotive engine oil.

"
I sometimes get asked "why are marine engine oils so expensive and why can't I just use regular motor oil in my marine engine instead?". Well, the National Marine Manufacturers Association Oil Certification Committee (click here for more info) introduced a four-stroke engine oil test and standard called the 4T certification. This specification is meant to assist boaters and manufacturers in identifying four-stroke cycle engine oils that have been specially formulated to withstand the rigors of marine engine operation. The certification was prompted by the growing influence of four-stroke engines in the marine market and their unique lubrication demands. So the simple answer is that regular road-based engine oil products don't contain rust inhibitors and won't pass the 4T certification. Lakes, waterways and the sea is a lot more aggressive an environment for an engine to operate around than on land.
"
I did not write this. Just something I found while researching this.

 

[Beefer]

Re: can I use automotive oil in boat

Re: can I use automotive oil in boat

I use automotive straight 30 wt oil. 30 wt is what Merc recommended for my engine, and I've heard that the mixed weights (10-40 etc) aren't good for marine engines. But I dunno.

 

[Don S]

Re: what type of oil do you use

Basically, if you don't want to use what Mercruiser recommends in their engine, then use whatever makes you happy.
Every type of oil has been used and is highly recommended by someone, someplace, at some time.
It usually sounds some thing like this " I use XYZ brand oil and have been using it for years with no problems". nothing to compare to, just a "works for me" statement.

Here is the Service bulletin Merc put out in 05. Follow it, or pick an oil that you like the looks of the lable on. If you change your oil and filter yearly or every 100 hours as recommended by all marine manufacturers, you will be fine with anything.

 

[sethjon]

Re: what type of oil do you use

Basically, if you don't want to use what Mercruiser recommends in their engine, then use whatever makes you happy.
Every type of oil has been used and is highly recommended by someone, someplace, at some time.
It usually sounds some thing like this " I use XYZ brand oil and have been using it for years with no problems". nothing to compare to, just a "works for me" statement.

Here is the Service bulletin Merc put out in 05. Follow it, or pick an oil that you like the looks of the lable on. If you change your oil and filter yearly or every 100 hours as recommended by all marine manufacturers, you will be fine with anything.

Don, AMEN to that. Maybe others will get this message.

 

[1CoeRay77]

Re: what type of oil do you use

15W 40 Valvoline HD Diesel engine oil. That was recommended by a mercruiser mechanic.

 

[nola mike]

Re: can I use automotive oil in boat

Re: can I use automotive oil in boat

Marine designated engine oil has more rust inhibitors in it than automotive engine oil.

"
I sometimes get asked "why are marine engine oils so expensive and why can't I just use regular motor oil in my marine engine instead?". Well, the National Marine Manufacturers Association Oil Certification Committee (click here for more info) introduced a four-stroke engine oil test and standard called the 4T certification. This specification is meant to assist boaters and manufacturers in identifying four-stroke cycle engine oils that have been specially formulated to withstand the rigors of marine engine operation. The certification was prompted by the growing influence of four-stroke engines in the marine market and their unique lubrication demands. So the simple answer is that regular road-based engine oil products don't contain rust inhibitors and won't pass the 4T certification. Lakes, waterways and the sea is a lot more aggressive an environment for an engine to operate around than on land.
"
I did not write this. Just something I found while researching this.

i've never seen anything coated in oil rust...

 

[zbadboy]

Re: can I use automotive oil in boat

Re: can I use automotive oil in boat

I also use the the straight 30wt dino oil. I use Shell Rotella T which is a industrial strength oil. Use it in my bikes as well.

 

[chomamma]

Re: can I use automotive oil in boat

Re: can I use automotive oil in boat

Probably more expensive because of marketing. In that they dont sell as much " marine oil".... But more likely is that the manufacturer make boaters "think" that marine oil is much better than crappy "car" oil..... Maybe..... or maybe not.

Can you guess what my opinion is......??

 

[sea wolf]

Re: can I use automotive oil in boat

Re: can I use automotive oil in boat

Considering that Mercruiser doesn't own it's own oil refinery, I doubt that they would contract with a major refinery & pay them millions of $$$ to produce "marine oil". Bunch of marketing b.s. imho.