Engine Oil 5W-30 or 10w-30?

[aidan545]

I was wondering is it ok to continue using 5w-30 Pennzoil Platinum Synthetic Motor Oil in my Yamaha F75 Outboard.

My manual says to use 10w-30 but the local store always has 5w-30 heavily discounted and I have been using it over about a year now.

Also since I have started using Synthetic Motor Oil .. is it true that you cant switch back to a none synthetic motor oil (even Yamaha Lube)?

I live in temperate climate near Seattle, WA.

Thanks.

[TownsendsFJR1300]

You can always switch back to dino oil without issue..

[robert graham]

BUT, if Yamaha says 10w30, then that's the weight I'd use....

[CatCam]

If it makes you feel better, I've used Pennzoil Platinum right after my break-in period. My motor is a 2004 F90 that I have over 600 hours on without any problems.

Now, as far as weight goes, I started out using 10W-30 but since I live in South Louisiana I've bumped up to 10W-40 -- being in WA stick with the 10W-30.

Now, on to your real question - 5W-30. I really don't think it will be a problem in WA cooler climate. 5W30 flows better when cold....

I say run it!

[TownsendsFJR1300]

Not to start an oil thread debate, (my engine is still just under warranty so I still use yamaha dino), I use full synthetic Mobile one (MC specific oil with a wet clutch) in my motorcycle. No issues, runs great!

Any issues what so ever (I wouldn't think so) with using a full synthetic after warranty for the larger F150? Of course keeping the same 10w40 or 20w40 (south Florida) weight oil.

Rodbolt and others opinions?

[CatCam]

True - true! I've been lurking around this site for years and have yet to read a thread that says, "I've ruined my Yammy because I used XYZ brand of Dino or Synthetic Oil". It's all a matter of preference and as long as you are not dumping gear oil in your crankcase you'll be okay.

My 2004 owner's manual was written before the FC-W (Marine API designation) came to fruition. My 2004 owner's manual tells me API SJ. And to dispel the "don't use synthetic" comments, Yamalube's new 4M 4 stroke oil is now available in full synthetic. Albeit, the cost of this new synthetic would equal the cost of a good steak dinner at a top end restaurant!

Yes, some oils may do a better job of preventing long term sludge, or deposits but as long as you change it at 100 hours or yearly you'll be alright. Now get that oil changed and start fishing!