my speedometer is off by 2.5 miles per hour how can I fix this problem ?? my speedometer shows 60 mph but gps and road side speed rador and clocking with stopwatch shows I am only going 57.5 mph. thanks any ideas should be a help since the dealers say its ok.

 

I haven't checked my mini, but I know my truck is off, my wifes car is right on at 70 per gps.... back in the day bike mags would show the difference on speedo on the data sheet.
I don't think you'll get 100%, factors that do play a roll is tire diameter. You might have different tires than stock?

just my 2 cents