I want to get my Cars speedometer certified

[carter840]

Well don't ask me why, but i think if would be cool if i could get my cars speedometer cerified. I know it can be done because many police cars have cetified speedometers.
How can i get this done?

[ELVATO]

Ooo, I think that would be cool as well. I wonder how much it costs...

[maxima lover]

I think a speedometer shop could do it, but I can't find any in my area. I want to get this done for sure since I'll have cameras on the speedomter to prove how fast I was going.

[Dondebob]

I know my speedo reads about 5MPH slower than my actual speed. This sounds like a good idea to me.

[Suf Daddy]

Yellow Pages.

Last one I saw was in Worcester MA.

-Suf DAddy

[Grifter]

Mine isnt "certified" but it is calibrated. I have an Xcal2 tuner for my car, I can adjust the tire height (in revolutions per mile) so that my speedo is set dead on. Both my handheld GPS and the built in GPS in my 9500i show the exact same speed as my speedometer. I havent run across any of those mobile trailer radar units yet to see how close that says to my displayed speed though.

Speedometers are only calibrated for one specific set of tires though. As the tires wear down, the revolutions per mile go up and you speedo will be slightly off again. Even if you get the same size tires in a different brand, the tire height will be different due to manufacturers tire specs and lug depth, and then the revolutions per mile will be off again from your "calibrated" state. Truck tires tend to be taller than the rated size due to the deeper lugs in the tread, and sport car tires will be shorter than the rated height. So having a calibrated speedo is really only calibrated for a limited time, then needs to be readjusted periodically.

[ELVATO]

Mine isnt "certified" but it is calibrated. I have an Xcal2 tuner for my car, I can adjust the tire height (in revolutions per mile) so that my speedo is set dead on. Both my handheld GPS and the built in GPS in my 9500i show the exact same speed as my speedometer. I havent run across any of those mobile trailer radar units yet to see how close that says to my displayed speed though.

Speedometers are only calibrated for one specific set of tires though. As the tires wear down, the revolutions per mile go up and you speedo will be slightly off again. Even if you get the same size tires in a different brand, the tire height will be different due to manufacturers tire specs and lug depth, and then the revolutions per mile will be off again from your "calibrated" state. Truck tires tend to be taller than the rated size due to the deeper lugs in the tread, and sport car tires will be shorter than the rated height. So having a calibrated speedo is really only calibrated for a limited time, then needs to be readjusted periodically.

Do you have an F150? I've heard the Xcals are for those.

Anyways, what many here want is getting the speedometer certified. Having an actual official paper saying that what our speedometer reads is correct.

In one of the Speeders videos, the LEO asked the guy if he had a certified speedometer. Would have been awesome to say "yea, here's the certificate."

[MEM-TEK]

*****

[Grifter]

Thanks for the welcome.

I have a Mercury Marauder. The Xcal can be used on pretty much any Ford (Lincoln/Mercury) from 1994 up as long as it has a OBDII port. You just need to find a tuner who knows what they are doing with your particular vehicle.

The only problem I can see with having a LEO certify that your speedometer is accurate is that now you lose the ability to try to talk your way out of a small speeding ticket with the "I think my speedometer must be off" excuse.

[MEM-TEK]

*****