Bought the 20" Tahoe LTZ polished wheels to replace theTahoe LS' 17" wheels. The new wheels come withGoodyear Eagle GT II285 50R20. When placed side by side the 20" wheels are slightly taller than the OEM's 17". While the wheel diameter isobviously larger the new tire size is not as tallas the original tires. I found a tire calculator web site and plugged in the numbers, program says the odometer will be off (faster) by less than 1 MPH. I also called 2 dealerships....both of them responded that it is not necessary to reprogram the new wheel diameter in the vehicles computer..... What does the forum experts say about this? By the way the change in the looks is very noticable...really like the 20's

thanks
Big D

 

No surprise that the dealer would say no reprogramming needed. Most odometers come out of the factory with some inaccuracy, and there's no laws that say how precise they have to be. That doesn't give you an excuse getting out of a speeding ticket, though. This is specific to GM or any manufacturer. My understanding that this is an industry "standard".

 

I did the same thing to my Tahoe. The dealer was able to reprogram my computer for the new setup. Here is a quote from ZX as to the reason why -

You should get a new VCI code that recalibrates the BCM for the 20" wheel/tire combo.
Not only will this correct the Speedo (even though it should read good now as the diameter is close) it will also provide the necessary new tire size including width to the ABS and Stabilitrak system so they use the proper algorithm when active.

The dealer will charge you to do it but it is worth the money. Have it done.

 

I don't believe these are factory stock size tires for the 20s. At least mine has 275/55-20.

 

Shark.
you are right.... i bought them off e-bay... the tiresare slightly wider than stock, but very close to the same height....

 

Just a quick question for the though! I'm taking my factory 20's off my 2007 Tahoe & replacing them with some DUB Dirty Dog 20's. Will I loose thefunction of my pressure sensors or is there anyway around that so it's all still functional with my new set up. Thanks for any information......

 

If they fit the new wheels, you can transferTPMs to the new ones. Reprogram them per your owners manual and you'll be good to go.