Speedometer off after bigger tires installed

[Taz56]

I knew it would be out, that was obvious. At lower speeds it is about 3 KM's per hour and at higher speeds about 5 KM's per hour.

 

I called my GM dealership and asked if they can re-calibrate the speedometer for the current tire size. This was the reply...... That just does not sound right and way to friggen expensive to adjust a 5KM difference. I am pretty sure I can just remember 95KM is 100KM. 

 

The price below is Canadian Dollars. 

 

There is no GM calibration for this at this time. Usually, we have to install an aftermarket speedometer calibration tool. The quote for this modification is $475.00 +Tax. This quote includes the part, and the installation. It is a specific part that would need to be wired into your truck.

[eppieguy]

Hypertech Speedometer Calibrator. 

[Taz56]

7 minutes ago, eppieguy said:

Hypertech Speedometer Calibrator. 

Do you have a model number? I put that into Google and what it came back with it said will not work with my 2019 GMC Sierra AT4

[newdude]

http://www.hypertech-inc.com/vehicle-results.aspx?AAIAID=510073

 

Last one down.  Part# 730129

 

GM will only calibrate to a factory offered tire size and nothing more. 

Edited November 13, 2019 by newdude

[Taz56]

Thank you.

 

[Taz56]

I put in my address (in Canada) when it goes to step 3 (shipping method) there are no options listed, and when I click next it tells me I have to pick an option. LOL.....

Edited November 13, 2019 by Taz56

[It's Tim]

Are you sure they sell direct?

[eppieguy]

I bought mine direct but I'm in the U.S.

 

[Sjordan]

Or, you could "put less miles on your truck" and use gps speed

[Taz56]

10 minutes ago, Sjordan said:

Or, you could "put less miles on your truck" and use gps speed

I have been using the GPS that is how I know how much it is out LOL.

Not sure what "less miles on the truck" has to do with anything however. Unless I am misunderstanding what you mean.

[Sjordan]

The truck does not think it is traveling as far per tire rotation as it actually is.  Because of this your truck will not accurately measure mileage, it will show you have driven less miles than you actually have.

[Cpl_Punishment]

1 hour ago, Taz56 said:

I have been using the GPS that is how I know how much it is out LOL.

Not sure what "less miles on the truck" has to do with anything however. Unless I am misunderstanding what you mean.

 

9 minutes ago, Sjordan said:

The truck does not think it is traveling as far per tire rotation as it actually is.  Because of this your truck will not accurately measure mileage, it will show you have driven less miles than you actually have.

To Sjordan's point, this means your warranty theoretically lasts longer. 

[Thomcat]

Dealer is capable of recalibrating the speedometer but only for any of the stock GM tire combinations offered. My RST option came with the dealer installed 22"  wheels. Truck was shipped with a transport set of 18" iron wheels and dealer installed the 22" rims with 50R275 tires. Prep included installation and balancing of the wheels and recalibration opf the speedometer for the wheel tire combo.Speed tested against roadside radar scanners and mileage against highway mile markers. Readings are dead on.

Edited November 13, 2019 by Thomcat
Edit tire size 22" 50R275

[Sierra Blues]

I bought the Rough Country one. I believe its the same thing but maybe they ship it to Canada?

 

https://www.roughcountry.com/speedometer-calibrator-90045.html?find=2019-gmc-sierra-1500-4wd-381260

[Taz56]

9 hours ago, Sierra Blues said:

I bought the Rough Country one. I believe its the same thing but maybe they ship it to Canada?

 

https://www.roughcountry.com/speedometer-calibrator-90045.html?find=2019-gmc-sierra-1500-4wd-381260

I'll check it out, thanks