Originally Posted by Zink01

Hi guys, I've been searching and lurking for awhile, but have not found any information on transmission shift issues with running larger tires.


Recently upgraded to 285/70 R17 from 265/70 R17 on my 2012 Suburban. Thought the slight increase (only 1.5 inches in diameter) would not have a major effect on how the truck ran. To my surprise, the fuel economy dramatically decreased, but I think that is due to the shift pattern of the transmission. The odometer is only 2 miles off from 60- 70mph. Dealer will not perform recalibration due to the tire size is not supported by Chevy. How have others worked thru this issue?


Anyone using Hypertech type product?


Thanks for the info. And sorry if it's out there already