Type of oil to use?

I need to change the oil, to get it ready for the season. All I have is an installation manual for the inboard. What type pf oil do I need to use? In all of my paper work I can't find the grade to use.

The motor is Mercury 5.0, carberated.

Re: Type of oil to use?

The wally worlds around here stock Mercruiser 4 cycle engine oil. I think that since your boat is designed to run at WOT for extended periods of time and is an automotive block stuffed with marine components, that an oil different than what you would use your 5 liter engine in a road vehicle which runs at 1/4 it's max rated rpm's for extended periods.

My thought would be 1. Additives not adequate for marine duty and it's harsh environment, and 2. Diluted oil (lightweight) like 10w 30 or so, might easily be blown out whereas a 30w especially designed for the occasion would stay in.

If you get no replies, I'd go to ww and see what sells. It's in the sporting goods dept, not where most engine oils are located.

Mark

Re: Type of oil to use?

Dan, I presume that is a small block chevy Mercruiser. Standard auto multi viscosity oil is not recommended. Quicksilver makes a 25W-40 motor oil that is recommended. SAE 30 oil is also recommended. I used the Quicksilver 25W-40 oil in my Mercruiser since I routinely used the boat is cold temperatures. There are other brands that are recomended. I think you need a FC-W rated oil.

Re: Type of oil to use?

NewfieDan said:

I need to change the oil, to get it ready for the season.

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Howdy,


If you do a search here, you'll find that people use every type of oil successfully.

If you want to use what Mercruiser suggests, look at the following.

http://www.mercurymarine.com/servic...ntenance/faqs/mercruiser/?category=fuel#MCOil

In the future, to get ready for the season, change your oil at the END of the season NOT the beginning of the season.

From Mercruiser:

Is it better to change my engine oil/gear lube at the beginning or end of the season?

It is better to change the oil and gear lube at the end of the season, prior to storage. Lubricants naturally accumulate moisture, combustion by-products, and other contaminants during use. It can be detrimental to store an engine or drive with large amounts of these contaminants present.

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Cheers,

Rick