I have my first big 4 stroke, 2015 Yamaha 200 SHO, on our tritoon. Getting ready to do the 100 hour service soon (first owner did not use it much). I have always had 2 strokes...

I use synthetic oil in most of my vehicles. But was just wondering if there is anything special about outboards that make it better one way or the other... synthetic vs. conventional oil? Also, which oil do most prefer?

I know this will be a lot of personal choice and opinions, but I appreciate that. Really looking for engineering facts also, if there is a true reason one way or the other.

Thanks in advance all!

Stay safe

Ken

I run Synthetic in mine as it doesn't cost that much more.

Highest quality oil recommended by manufacturer. Really shouldn't even be a question anymore. Just do it.

We use a Synthetic Blend Mercury Marine oil in all of our customer's products unless they request otherwise. Synthetic oils are just flat out better than conventional oils. Go synthetic, and make sure you use a marine rated oil. Yamalube would be OEM for that engine.

I was told to use Yamalube conventional oil in my 4stroke. I was also told the reasoning being it has special additives to withstand the moisture that builds up in the crankcase from frequent starting and shutting off of the motor without running it long enough to “cook off” the moisture.