GOOOOOOD question...personally I think it's a dealership conspiracy If any of my wrenching experience has taught me anything, its that modern, computer-controlled vehicles have fairly flexible ECMs in them that can be programmed to fix signal problems by dealership computers. Meaning, that I should be able to take my X to a Nissan dealer and have them re-program the ECM to accept a different standard tire size (the 2.4L POS and the 3.3L VG33E use pretty much the same computer, yet they have different tire sizes...hmmm....). I have also been told that if I were to bolt on a factory supercharger to a non-S/C X engine, I could take the ECM to the dealer to be programmed to accept the changes. So why can't they re-program my ECM to accept that I am now using different-sized tires? Or a different gear ratio? Maybe a Nissan tech can respond to this one for me. Or maybe not. I can't be too bitter towards dealers...one of these days they'll have an important recall for the X like every other 4x4 vehicle out there has all the time. My kudos to Nissan for building the coolest 4x4 ever. Thankfully they're fixing some of its weak points in the '05. Time to go back to sleeping on my desk at work!