I've e-mailed Shell the below to see if they have any comments as to why my motorcycle performed worse on V Power Nitro + than on normal Shell. If I get a reply I'll post it:
I ride a single cylinder motorcycle which revs up to about 8000 rpm (a BMW G650 X country) with fuel injection from 2007. I tried the new V Power Nitro for about a month and then switched back to the standard Shell fuel and my findings were quite odd. I found the bike much more responsive at lower revs on the normal fuel and it even stalled a few times when cold when using the V power. The fuel economy remained broadly the same (trended towards a slight improvement with V power but I'd have to do a longer test to ensure it wasn't down to chance / weather / me getting angry at car drivers and thrashing it occasionally. It certainly was not enough of an improvement to justify the increased cost.
I wonder if you have any idea why this would happen? In the manual for the bike it does specify 95 octane fuel and so I wonder if it would need setting up to make the most of 99 octane / use it correctly? Or could it suggest a potential engine issue?