Merc 170 Oil Question

[jayrodoh]

Changing the oil for winter storage. The cap on the engine says 10W-30 but the dealer says 25W-40. I've found conflicting info but nothing definite. What should I use?

 

[Fishermark]

Re: Merc 170 Oil Question

Your engine is over 20 years old. Oil formulations, etc change over the years. Here's the latest from Mercruiser:

 

[180shabah]

Re: Merc 170 Oil Question

10W30 will work fine, but 25W40 is better and is what Merc is now recomending.

 

[jayrodoh]

Re: Merc 170 Oil Question

Great, thanks guys. I'll go with the 25W-40.