Lots of discussion about this, 10w40 is ideal for the UK as a whole whereas if you live in warmer climbs where you don't get frosts, 15w50 would be marginally better suited. If you live in short duration sub zero cold climbs you might go to a 5w40. If you don't ride in the winter months either 10w40 or 15w50 will be fine depending on what is easiest to get and best value. Note "best value" not cheap. Andy
According to my owners manual for the 1098, 15w-50 is suitable down to -5C if you ride in colder than that...................Good Luck Top end >+40C I use Motul 300V when I used the 10-40 I found the gearbox didn't seem to be very amused with it. Changed to 15-50 and its been fine ever since I seem to remember posting this up before and getting stick from one of the self proclaimed experts, but it is the Interweb so there is always an expert. Just my experience YMMV
