I'm thinking of moving to a slightly larger tyre size. 5% larger in fact. My speedo currently reads about 5% fast, so the larger tyres would compensate for this & the speedo should read accurate.
But, if were to throw caution to the wind and go to 10% larger tyres, my speedo would then read about 5% slow. How does this leave me from an MOT point of view - ie, would I need to recalibrate the speedo? What's the allowed tolerance for MOT purposes?
Thanks, David