Hmm. was in asda today n noticed they had castrol gtx 10/40 4 ltr for £12 so seeing as the GS is due an oil change I purchased it ..when I was puttin it in the boot of car I noticed on the label it was synthetic ...
will it be ok to run it in my R1100GS ? cheers 
will it be ok to run it in my R1100GS ? cheers
