Pontoon Boat & Deck Boat Forum

Hi Guys
Been using the pontoon (2008 90hp Merc 4 stroke) pretty heavy over the month of July. Checked my oil and looks like it needs a slight touch-up (Is that normal?). I have it serviced every year which dealer claims to put synthetic in. Should I add the mercury brand 25w-50 or do the mercury 10w-30? I will be using it heavy for rest of summer then the odd weekend over fall.
Thanks
Smitty

I have a 60hp merc on a 22ft toon I ave around 150hrs plus per yr I change my own use Pens-oil

I would think most boat dealers would be using 10W30 oils. Some dealers are buying it in 55 gallon drums--in bulk--cheap.

I've switched to 10W30 Mobil 1 Extended Performance in my Yamaha F150--which on automobiles is good for 15,000 mile oil changes. It's a superior oil to regular Mobil 1, which is also very good. When I changed my oil the first of the Summer, my old oil (2 years old) looked brand new.

FYI: I earlier went to Fram.com and cross referenced my Yamaha oil filter and found it to be the same Motorcraft oil filter used on the 2.0 liter Focus 4 cylinder engine.

This is interesting. The manual for my 2009 Mercury 90hp 4S calls for FC-W 25W40. The automotive oils don't have the FC-W rating.

I can rarely find Quicksilver brand of FC-W 25W40, so I order Sierra brand.

Hello.
A few years ago, right after we purchased our new to us pontoon, I went to a local, trusted, "Mom and Pop" style marina for my oil in my 4S 75 Merc and when I asked for Quicksilver, he handed me Sierra. I have been using it and going there ever since... Safe boating.

Sincerely,
Rich