My settings for tire size were a bit confusing. The stock setting in "current tire" was 28.76 However when I put my real tire size in the width/profile/rim (275/40/17) the new tire size was 25.66 Why was the computer setup with such a different tire size? I then put my new rear gear size in and the transmission adjustment was changed to a -10.79 Is this right Sounds like the shift is either going to be softer or sooner. Something I dont is a good thing. Can someone clarify this for me?