do i need to recalibrate for tires?
i am installing 235 85 16's and i know my speedo will be off. i was considering a super chip for both the fuel eco tune and the tire calibration. i have heard some rumblings that my 03 4.7 wj does not need adjusting because of the method the system uses to calculate the speed. if that is the case i dont want to spend $350.00 for the fuel eco program only. pretty expensive for me to get this wrong. help!!!!!!!!!!!