I always use the limit +10% rule, keeps you within the ACPO guidelines and lets you glide past lesser mortals afraid to do the true speed not the one indicated on thier speedos (although why they should wear swimming trunks in the car....? ) , but since the proliferation of satnavs most people know the true speed anyway, shame really but often they are still wary of exceeding it.
Illustrates your mentallity. You are clearly more interested in avoiding prosecution than complying with a speed limit. The speed limit is a maximum permitted speed, not a minimum. Is it necessary to be so childishly insulting to 'lesser mortals'?
So now we tear-a**e around when we do the true speed limit and not the one shown on the speedo?
ACPO guidlines or 'true speed'; which is it??