Adjust speedometer for non-stock tires

[kodiakdenali]

What options are there for correcting the speedometer when running non stock tire sizes? I understand the dealer can do that for you, but they will only change it to another optional stock tire size. I'm sure there are multiple ways to do this, what's the most reliable/least invasive?

[Steve-2019]

One option is the Pulsar LT that will do this along with many other options. 

(Of course not an option at this time until they get back in stock)

[eppieguy]

Dealer can't do it, or won't do it, I used Hypertech Speed Calibrator.

 

[kodiakdenali]

How does the hypertech work? Does it need to stay plugged in? I don't want to have something attached to the odb2 all the time.

is it easy enough to do that you could re calibrate often? unfortunately my winter and summer tires are not the same size.

[eppieguy]

Not plugged in to the port, it’s plugged in to the harness under the dash, easily removed, program it on a pc before you plug it in, plug and play, easy.

[Z06JPB]

On 3/19/2021 at 12:19 PM, eppieguy said:

Dealer can't do it, or won't do it, I used Hypertech Speed Calibrator.

 

Exactly this, even if you are using an optional factory wheel and tire size.
 

Only way they will do a calibration is if you purchase a GM Parts and Accessories wheel package AND you use the specified tire size. 

[Kickerz71]

Can I ask for feedback on the Hypertech programmer

[eppieguy]

1 hour ago, Kickerz71 said:

Can I ask for feedback on the Hypertech programmer

I like it, no issues, easy to program, easy to remove if you’re afraid of warranty issues. 

[kodiakdenali]

This is the one that comes up when you use hypertech's search, is this what you have?

 

Speedometer Calibrators Inline - Part #730129

 

 

[eppieguy]

1 hour ago, kodiakdenali said:

This is the one that comes up when you use hypertech's search, is this what you have?

 

Speedometer Calibrators Inline - Part #730129

 

 

Yup, thats it, I got it on Amazon.

[kodiakdenali]

51 minutes ago, eppieguy said:

Yup, thats it, I got it on Amazon.

how does it work? how do you tell it what the tire size is? looks like it plugs inline with the instrument cluster?

[eppieguy]

You hook the black box up to a PC or laptop, it asks you Stock Tire Size, then new tire size, you then hit program, wait for it to do it's thing, then plug it inline with the harness of the truck. 10 minute process. 

[kodiakdenali]

ah...simple yet disappointing. I wish it had just as simple UI on the box itself. I looked up their software, they distribute it only as a .exe, no ready to run binaries, no .deb package. Its unfortunate when things like that present an impediment to some potential customers using an otherwise useful product.

I wonder if the tire shop has the tools necessary to reprogram it? Honestly its really disappointing that cars don't have a factory integrated system for adjusting for tire size, or an automatic calibration process you can run that would calibrate the speedometer vs GPS data.

[316hepster]

I have one from rough country for sale if you’re interested. It’s the inline type. Has worked well for me. Ended up w 2 of them. 

[BrianABP]

On 4/17/2021 at 12:17 PM, 316hepster said:

I have one from rough country for sale if you’re interested. It’s the inline type. Has worked well for me. Ended up w 2 of them. 

 

sorry to bump an old thread but do you still have that extra one?