What Synthetic Oil to use

[Shaun78]

I want to put synthetic oil in the boat. I used to use the Quicksilver regular 25W40. Can I just use Mobil 1?

 

[Robj]

Re: What Synthetic Oil to use

Yes you can use Mobil 1. Lots of guys in this forum use it. Just make sure the oil is of the recommended viscosity.

Have a great day,

Rob.

 

[Shaun78]

Re: What Synthetic Oil to use

What should I use? I don't think they make a 25W40 like the Quicksilver. I guess the closest is probably 20w50

 

[Bondo]

Re: What Synthetic Oil to use

Ayuh,........ I run Mobil 1 in 15W-50 in my 4.3LX.........

 

[Dante04SRT]

Re: What Synthetic Oil to use

How old is the boat?

If its more than a season or two, I'd stay away from the synthetics. Some may disagree, but I've had more trouble trying to switch from dyno to synthetic oil. Its been explained to me this way:

An older motor (a few years old) has run using dyno oil and has little pockets or areas where "gunk" (technical term) has collected; usually around gaskets and such. When you swap this motor over to synthetic, the synthetic will clean those pockets. Not a bad thing by itself, but when those areas are cleaned, some of that "gunk" may have been a block to an oil leak in a gasket. I've seen more oil leaks as a result of dyno to synthetic swaps than I ever thought imaginable.

I use Synthetic in my car, because I bought it new and it has always run Synthetic... The boat and my other vehicles will always run dyno oil for the above mentioned reason.

Some may disagree, this is just something I've noticed a LOT over time.

 

[Chris1956]

Re: What Synthetic Oil to use

Shaun, it is critical to use the proper oil in your sterndrive. If MerCruiser recommends synthetic oil that is the same as Mobil 1, then use it. if not, I would not try it. The motor oil in a sterndrive takes a real beating and auto oil simply won't stand up to this use too long.

I used the non-synthetic Mercruiser 25-40 oil. It was ~$3/qt, which was a bit more than the SAE-30, which was also recommended by merCruiser.

 

[sickwilly]

Re: What Synthetic Oil to use

What about the new semi-synthetic merc oil as a compromise. Its only $5 more for the gallon jug at my marina.

 

[Shaun78]

Re: What Synthetic Oil to use

Thanks, i'll stick to the Quicksilver regular

 

[craigie]

Re: What Synthetic Oil to use

Hi,

I have a Johnson 140 hp 4 stroke. 2 Years old.

Till now for servicing been using Evinrude synthetic oil and over here in Scotland it costs a staggering $120 per gallon, it is supposed to be changed every sixty hours.

I do over 60 mhours a week in the summer so it is costing me a fortune. Our local dealer insists that we only use the Evinrude stuff.

Surely I can use any good quality synthetic oil? I can get Mobil1 for example for $60..

Any advice guys???

 

[Don S]

Re: What Synthetic Oil to use

Any advice guys???

First of all, welcome to iboats.
Best advise I could give is for you to start your own thread, don't just tack on to the end of someone elses. Even if it is closely related.
Next, post your question over in the Johnson/Evenrude Outboard forum since you have an outboard.

 

[Dakota47]

Re: What Synthetic Oil to use

Mobil-1 is OK.