15W50 oil or not

[PixelPaul]

never realy need to top up my oil as of yet.. and gona do an oil change soon. i jst noticed on the service sheet of my bike from the dealer that they ave been putting in 15W50 oil in my bike... which is not the standard.. i have a 05 zx6r btw.. u guys recon this is good bad or nothing at all really. as people always say different things like that grade is usualy for older bikes or V Twins and so on.

[MadKaw]

Interesting question.
Personally, on a newish model bike with not too many K's I'd go with a 10w 40/50.
Given that its summer and start up temp is higher I wouldn't think 15w 50 would be a problem. If its good oil it will be fine.

I'm running 10w 50 semi in both my zx10r and zxr750r race bike. I am changing to a 5w 40 in the zx10r at the next oil change as it will be through winter (and I got some full synthetic at the right price).

[Nanna10r]

Yeah Dave has the good oil on this one.
In my experience it depends on your gearbox, Better the changes thinner the oil you should use. I went back to Semi syth cause of the False neutrals on "Tiggr" much improved.
As for climate i wouldn't know, it's not a factor up here, goes from Hot to FArken hot.

[Gosling1]

.... as people always say different things like that grade is usualy for older bikes or V Twins and so on.

they are probably referring to the straight 50-weight oil that is recommended for old Ducati's, Harleys etc. 15W50 is OK, as long as you top up with the same weight oil. 10W40 or 10W50 is the go, as MadKaw has said. ( 10W40 is probably the recommended oil anyway ?)