When the ADV screen was on air brake high the turbulence caught the peak and tugged it around, low down it does not. Besides the peak on the new Shoei is designed in a wind tunnel, so said the man in the shop with the big
windows
Yes the turbulance is or was the problem with the Arai tour I allways had my screen on low as the wind itself was not the problem !
All that said I cannot use the Arai tour on the XR as the peak shakes the helmet so badly at speed I cant see properly !
The Shoei is reputed the best peaked lid for road use

but seriously if you make a point of refuelling with a specific amount (as post above says) & reset tripometer then you may get a differing result ?

, my mate however continues to get 56