MD5 said:OK, I just checked my speedo on the way home.
Indicated speed 70 - Radar hunts between 69/70, but spends more time at 69
Indicated speed 75 - Radar hunts between 74/75, but spends more time at 74
Indicated speed 80 - Radar hunts bewteen 79/80, but spends more time at 79
That's close enough for government work. I don't think you can get much closer than that to true speed. I just wished I'd checked the speedo before the tire swap.
By the way, I also checked 30, 40, and 50 mph all with the exact same results. The radar was from one mph slower to exactly the speed indicated.
Good to know, now I won't go with that 45 series tire when I replace. Thanks for the great feedback and info.