D max and tire size??

[JohnnyFamous]

Just took delivery on my 2022 Denali. My first diesel so I was reviewing the operational manual, not typically something I get hung up on. I noted in it is said do not to change the tire size or this may affect the motor operation. WHAT?

I have ordered a set of 24 wheels with 305 35 24. So this will decrease the overall height by about .5 of an inch. Can the speedometer be calibrated? how will this actually affect the motor as per the manual??

 

[Pro299]

Is that in the regular owners manual or the smaller diesel supplement to the manual? I don't remember seeing that. Either way it sounds more like a CYA legal statement than anything else. The only caveat is that some dealers will look for any excuse not to cover warranty items. "See there, you changed your tire size, that explains why the air filter keeps falling off."

 

[CTown Duramax]

I wouldn't do it. A lot of things run off the speed/distance traveled information. I think if you need to change tires, it must be recalibrated. This may be especially true of diesel.

 

[JohnnyFamous]

I wouldn't do it. A lot of things run off the speed/distance traveled information. I think if you need to change tires, it must be recalibrated. This may be especially true of diesel.

Respectfully, I am not one for sticking with anything stock, can these actually be re-calibrated? I am told gm won't allow calibration, all hearsay. The issue I am finding is these things are so new, no one I call seems to actually have any real answers aside from opinions.

 

[steiny93]

Appears their are calibrators available and if it's 'Global B' it can use gps intel to change. See this thread: https://www.gm-trucks.com/forums/topic/241698-speedometer-calibration-with-larger-tires/
But... .5 inch is a pretty small amount you may want to see what the actual difference is.

 

[JohnnyFamous]

Appears their are calibrators available and if it's 'Global B' it can use gps intel to change. See this thread: https://www.gm-trucks.com/forums/topic/241698-speedometer-calibration-with-larger-tires/
But... .5 inch is a pretty small amount you may want to see what the actual difference is.

that would be pretty cool if it calibrates itself... Fingers crossed. I will give it a go and see what happens. Wheels and tires are a few weeks out yet but ordered, lets's hope I don't have to wait as long for them as I did the Denali.

 

[CTown Duramax]

If you don't want to do it yourself, the dealer should be able to do it for you since GM sells 22 and 20 inch wheels for the Tahoe diesel.

 

[david1523]

Has anyone seen an answer to this? Just picked up my 22 duramax Denali and I want to put a set of 24s on, but I had no idea that this could possibly be a thing.

 

[ljn21]

Has anyone seen an answer to this? Just picked up my 22 duramax Denali and I want to put a set of 24s on, but I had no idea that this could possibly be a thing.

No programmers available for the 21+ Tahoe/Yukons yet. No one has figured out how to crack the ECU yet which are different than the Sierra/Silverado trucks.

 

[olyelr]

Just took delivery on my 2022 Denali. My first diesel so I was reviewing the operational manual, not typically something I get hung up on. I noted in it is said do not to change the tire size or this may affect the motor operation. WHAT?

I have ordered a set of 24 wheels with 305 35 24. So this will decrease the overall height by about .5 of an inch. Can the speedometer be calibrated? how will this actually affect the motor as per the manual??


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Why do you have 285/45/22’s in there…that isnt what the new rigs come with. They come with 275/50/22’s.