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Posted

Struck out with the Hypertech In-Line (plugs are physically different).  Anyone have any luck on a 2022 refresh yet?  Went from 17" to 20".  Even thought the 20's are a stock chevy wheel/tire combo - dealer won't/can't update as Chevy won't help.  Thanks!

Posted

What is the difference in tire sizes? If the overall tire diameter is the same it wont effect the speedometer. I will say that most dealers don't go that anymore and a tuner will most likely have to do that for you.

Posted

went from 30" to 32.5". Not much, but its off by about 4 mph (slower) than actual at 70.  Lots of highway driving between 70 and 85 posted here in Tx.  Just want it accurate to keep from feeding the bears.

Posted (edited)

Find a tuner in your area, they should be able to change the tire size without a tune on the counter. Maybe call around some tire shops.

Edited by jaxcam02
Posted
7 hours ago, jaxcam02 said:

Find a tuner in your area, they should be able to change the tire size without a tune on the counter. Maybe call around some tire shops.

And what tuner would they use?

 

You can't actually tune the 2022 Refresh trucks, they are not supported by anything yet. If HyperTech or any of those other handheld devices don't work, he'd be out of luck.

Posted (edited)
7 hours ago, CamGTP said:

And what tuner would they use?

 

You can't actually tune the 2022 Refresh trucks, they are not supported by anything yet. If HyperTech or any of those other handheld devices don't work, he'd be out of luck.

I don't know much about tuning but I know you can't get in and do a full tune on the refresh trucks yet but when my tuner use HP tuners on another one of my vehicles, he was able to cable into the car and change the tire size settings without actually tuning the vehicle. Thought it would be possible to do on the refresh too maybe and probably the only option worth investigating at this time. I'll ask my tuner if its possible.

Edited by jaxcam02
Posted (edited)

Welp he said your basically screwed since the whole programming is encrypted and no one has broken it yet. Think of it this way, your mileage on the odometer will be lower than the actual mileage which means you'll have your warranty longer. Just need to put the stock wheels and tires back on before you take it to a dealer for warranty issues.

Edited by jaxcam02
Posted (edited)
On 8/15/2022 at 2:07 PM, cccjrsbox said:

Struck out with the Hypertech In-Line (plugs are physically different).  Anyone have any luck on a 2022 refresh yet?  Went from 17" to 20".  Even thought the 20's are a stock chevy wheel/tire combo - dealer won't/can't update as Chevy won't help.  Thanks!

 

 

Dealers can program to factory sizes only.  If you have a non factory size tire, then yea the dealer and GM will say no go.

 

If your truck could have been ordered with 20s, they can flash it at a cost.  

 

Have them pull up this document:  PIT3271M: Guidelines When Changing Tire And Wheel Size

 

IF you have a good dealer, you might get lucky and they can request the programming for the 20" wheels 275/60R20 tire size.  

Edited by newdude
Posted
5 hours ago, newdude said:

 

 

Dealers can program to factory sizes only.  If you have a non factory size tire, then yea the dealer and GM will say no go.

 

If your truck could have been ordered with 20s, they can flash it at a cost.  

 

Have them pull up this document:  PIT3271M: Guidelines When Changing Tire And Wheel Size

 

IF you have a good dealer, you might get lucky and they can request the programming for the 20" wheels 275/60R20 tire size.  

They won't do it and have been asked by gm not to do it (supposedly the last time I asked a gm dealer to do it) unless the tires are installed at the dealer.

Posted (edited)
56 minutes ago, jaxcam02 said:

They won't do it and have been asked by gm not to do it (supposedly the last time I asked a gm dealer to do it) unless the tires are installed at the dealer.

 

 

Nothing in that PI I referenced mentions as such 🤷‍♂️

 

"Technically" all a dealer would have to do is verify to GM Techline is that the customer had the dealer install a set of factory take off wheels the dealer had for sale, verify that the customer's truck "could" have been optioned with those from the factory and GM would issue a calibration for that specific VIN.  

Edited by newdude
Posted (edited)
18 minutes ago, newdude said:

 

 

Nothing in that PI I referenced mentions as such 🤷‍♂️

 

"Technically" all a dealer would have to do is verify to GM Techline is that the customer had the dealer install a set of factory take off wheels the dealer had for sale, verify that the customer's truck "could" have been optioned with those from the factory and GM would issue a calibration for that specific VIN.  

Yea its a bit hit or miss. but becoming more miss with GM dealers on this topic over the last couple of years in my experience. The last dealer quoted "warranty claims" as the reason why GM asked them to stop changing tire size calibrations unless the dealer did the work.

Edited by jaxcam02
  • 2 weeks later...
Posted

I went thru the headache of trying to get mine done from 3 different dealers and it proved to be futile.  I put on 20" AT4 wheels (going from my 18" stock) and the overall difference is only 1mph when going 70-75 on the highway.  If that bothered me enough I was going to go the Pulsar route which seems to be the best option aside from living with it.

Posted

o wow didn't know this was being talked about. I'm in Canada and I have 35" Wheels on my refreshed AT4.

 

I got told the same thing as you all. Dealers can only change tire sizes to the one the trucks can be optioned with. I'm out of luck since my tires are 35", the speedo is off by 10km when I'm going 100km.

 

The only workaround visually I've found is running waze in android auto, as it shows GPS speed in the bottom right corner. Its small but its something.

 

Kinda makes the heads up display useless, Even though I know that I'm going 10-15km faster than my speedo shows, psychologically it has me passing people and getting frustrated.

 

I foresee some tickets in my future.

  • Like 1
Posted (edited)
7 hours ago, GM90 said:

o wow didn't know this was being talked about. I'm in Canada and I have 35" Wheels on my refreshed AT4.

 

I got told the same thing as you all. Dealers can only change tire sizes to the one the trucks can be optioned with. I'm out of luck since my tires are 35", the speedo is off by 10km when I'm going 100km.

 

The only workaround visually I've found is running waze in android auto, as it shows GPS speed in the bottom right corner. Its small but its something.

 

Kinda makes the heads up display useless, Even though I know that I'm going 10-15km faster than my speedo shows, psychologically it has me passing people and getting frustrated.

 

I foresee some tickets in my future.

 

I run my dash set to 'inch' units, so have been doing the 'remember to convert' mental exercise for many years.  

 

I think I'd find 10% speedo error (10km at 100 kph) to be even easier.

 

You'll likely do fine. 

 

(I don't really care if it's mph or kph, but I like to monitor fuel economy for ****** and giggles, and much prefer mpg vs L/100km. 

I'd like it even better if 'miles / imperial gallon' was available. 

I likely would just convert if kpl  (kilometers per litre) was the metric version in use.

 

 

 

Edited by redwngr

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