Speedometer Error

[Chevy2DMAX]

It appears my speedometer is off by about 2 mph. The service guy says GM considers that to be in the normal range, that 4 mph is outside the normal range. Does that sound right?

[jalanzrr]

Same as mine- 2 mph.

[Wing'n'it]

That seems to be pretty close. Checked mine against the GPS after I changed tires from OEM to 265/70R17 and found odometer off by 4% (as expected) but speedo was within 1-2 mph slow. It must have really been off with the OEM tires!

BTW, had the bosses '00 M5 BWM into the shop a couple of months ago because after they changed the instrument cluster the speedo was off almost 10 mph. They claimed it was within specs!! I did some research and found Fed standards are within (+/-) 10%+ 4 mph. Can you believe that!

Sorry for the long post, but IMHO 1-2 mph is pretty close, unless you want to use a programmer and play with tire sizes to tweak it.

Good Luck!

Mike