As gas Mercruiser owners, we know the factory recommended lubricant is the Mercury Quicksilver 25W40 conventional oil. I am using it now in my Merc GM 6.2 blocks. In my area, marinas sell this brand for around $36.00 for a four-litre jug.

There's so much written about engine oils - some confusing.

I've read that the Shell Rotella Triple Protection 15W40 is a good alternative. I saw this brand at my local auto PartSource store on sale for $25.00, for 5.5 liters, regular price of about $28.95. This oil is made for the Diesel engine market, but I believe some gas boaters use it. Do you? If so, do you like and recommend it?

Some use straight 30 weight oil.

So what's your engine oil experiences, likes and/ or dislikes?

If you have the marina do your oil changes, do you even know what they put into your engines?

If you are a do-it-yourselfer (I am) then you get to choose your oils. What's your preference?

Feel free to go all out in this topic. Perhaps you want to write about brands, blends, or conventional versus synthetics. I used Volvo synthetic on my last Volvo GM block boat.

Cheers all

Steve