Engine oil

[VNA]

I go higher: API SL. No problems with clutch, or engine. It is BETTER, not worse, you know?

Eh?  What oil are you using?

VNA goes off and googles some more..........................

This is even more confusing than I first thought.

Here an interesting article I found on the web.  It's just a random article on the web, so take it with a pinch of salt, but the fella does seem to have been doing his homework.......  http://www.post610.org/truth_about_motorcycle_oils.htm

What is important to note is this: Just as 10W-40 and 20W-50 weight oils are exempt from the
zinc/phosphorus limits put in place by API SJ specifications, these same grade oils are exempt from the
fuel efficiency mandates that the SJ rating requires. Thus, it is not necessary for motor oil
manufacturers to add friction modifiers to their 40 and 50 weight motor oils.
Therefore, it cannot be assumed that just because an oil meets API SJ specs it must contain friction
modifiers. It doesn't have to. Some automotive 10W-40 and 20W-50 motor oils may contain no friction
modifiers whatsoever. This could only be determined by speaking with the manufacturer themselves.
Unfortunately, if that manufacturer also carries a motorcycle specific brand of oil, it is likely that they
would point you that direction and avoid answering the question. This is because their motorcycle
specific oil generally costs more and makes them a better profit.

More googling, cos Slaninar and the above has me wondering if API SL is available with a picture of a motorcycle on the tin.  Of course if it's API SL car oil 10/40 it might be exempt from all those nasty additives as our man above claims is possible, but being sure is a nightmare.

So what about this - it meets the old SG spec - which I think is what the owners manual asks for - it's marked as JASO MA and has a picture of a motorcycle on the front - so your clutch and gear box will be fine - but is also rated API SL - so has been tested to a current standard unlike the Silkolene stuff I'm currently using.  The price is a fiver more, but considering all we can go on is specs, this looks way ahead of Silolene.  MOTUL 5100 4T 10w40  33 quid 50p

http://www.opieoils.co.uk/p-915-motul-51...ester.aspx

If you want fully synthetic;  43 quid.

http://www.opieoils.co.uk/p-912-motul-71...ester.aspx