Tire Size Adjustment

[penance]

I have been testing over the last week adjusting my tire size. I am currently running 35" tires, they measure 34.6 actual, on my 2016 GMC Sierra Denali. It seems no matter what tires size I put in either through easy tune or adjusting the tire size in advanced mode the speedometer always stays the same. I have tried 33, 33.5, 34, 34.5, 34.6, 34.75, 35, 35.5, and 35.75 and they all are reading 64 mph verified by 2 GPS and 1 road side radar sign at the speedometer showing 60mph. I'm curious if this is a bug? I noticed a few other threads regarding this same issue.

[mikel]

Yes, thus far we have been unable to affect the speedo, we are still investigating.

[penance]

I was able to work out a return with Autoanything. I'm curious with the growing list of unsupported features on the newer model GMC and Chevy trucks why are these even listed as supported vehicles? It would seem to me that if most of the features don't work it should not be advertised as being supported.

[Phoenix95]

I am having the same issue with my tuner. No mater the tire size put into the tuner for adjustment, remains 2 mph off (GPS verified). I agree that this is frustrating, considering that this was the primary reason for purchasing the tuner. With a 15% restocking fee assessed to any returns, this falls well within the realm of BS. Will there be a patch to correct this issue or did I just purchase a $400 paperweight?

2016 Chevrolet Silverado LT Z71 5.3L

[ffwatson21]

same here. i have 34.1" tires ive tried 33"-35" in adjustable parameters and no change. not to mention the updater fails and no wifi. why is this even on the market right now??

[fpdsniper]

I actually measured my tires on the truck. They are listed as 33" (Lt275/70/18), but actually measure 32.25". I put this number in the tuner, and now the speedo is right on the money.