4 stroke Engine Oil

[stuartbull2]

Yammaha 50 four stroke -should I always use the recomended Yammy engine oil (or similar marine brand) or can I use a good quality (and readily available) car engine oil, presuming the spec is exactly the same i.e 10w-30 or 10w-40 APIse sf sg sh sj

Cheers
Stuart

[ian parkes]

Well Iam about to change the oil my suzuki with a decent car oil . I can't see any reason why not .
All my suzuki manual specifies is the grade and spec of the oil . Nothing mentioned about any specific make or marine oil .

[stuartbull2]

Thanks for your comment Ian,rather what I was thinking /hoping
Stuart

[matt h]

well Yamaha dont make oil, it would be re badged Shell or something,as long as the viscocity is the same then i wouldnt hesitate!!

[Searider]

Originally Posted by matt h

well Yamaha dont make oil, it would be re badged Shell or something,as long as the viscocity is the same then i wouldnt hesitate!!

Matt,

It's not just the viscosity that's important - the other letters are the important bit.

"S" for spark ignition engines
f,g,h and j as the oil grade improves.

A 10W/40 oil could be mineral, semi-synthetic or full synthetic and could cost anything from £2/l to £10/l because of the different quality.

An Sj car oil of the correct viscosity should be just fine.
I reckon it might be a semi-synthetic.

[stuartbull2]

Thanks all,I guess I will be visiting my local Autostore this weekend,my earlier fear was (as I am sure I have seen on a Yamaha Advert) was that the marine 4 stroke oil had extra adatives to cope with the marine environment.
However I can now that a spec is a spec and as long as it meets that then Ok to use.
Now who to get the filter from?

Stuart

[OceanEco]

You do not want to use synthetic oil in suzuki 4 strokes unless you want to void your warranty. if you read the manual is says to not use synthetic oil.

[jyasaki]

Why go to an automotive oil? The only reasons I can see to change are price and availability.

On price, you've spent, what, maybe 5000 to 8000 pounds on a motor (size depndent, of course.) Does a couple more really make that much of a difference?

On availability, well, you've got me there. Though I will say that even without a chandler nearby, the stuff is easy enough to order online.

But, on the thread subject, the additive package in the marine oil probably has a bit more detergent and a higher percentage of long chain molecules; meant for high revving engines tuned more for output than for emissions (opposite what cars are.) Using automotive oil probably won't do much damage short term, but I would change it more frequently if I were running it.

[Note: My suppositions on the make-up of oils is just that. I have no idea if they are actually different. Just that it's easy enough to avoid the whole question, in my opinion.]

jky