i've checked mine many times and its about 10% off...figured this out with my odometer and mile markers, my odometer says i go about 9/10 of a mile for every mile marker and verified this with the highway radar speed reminders that are posted around in different areas,so u can just do the math and stay under the limit that way...do 22 1/2 ull be at 25, 33=35, 41=45,50=55,63=70 and so on....

Lonnie
Auto Parts Professional
95 sportage sold but not forgotten