The ECU will see the same as stock *until* you reprogram (only a GPS knows your parameters are incorrect). So, no, there would not be an affect on the calculations.I have been thru both of the the forums about the clutch recall. I understand the temperature will be a "calculation" based on other readings form the vehicle. I have not seen anything in the thread about tire size. This has a HUGE effect on the calculation. I have a Sahara and put on the Rubi Wheels and tires, I have not make the change to the ECU -- Threrefore, the Jeep is going faster then it really is ! I would assume this will cause problems with the calculation. Am I wrong ?? If not, then the dealer will need to mkae the update for the tire size, AND in the future when you change tire size it will cause problems ! ! Again, please someone correct me if I am wrong.