The tires only seem to me to wear out depending on whatever dodge was putting on originally if it was good or not, sometimes they use junk sometimes not. The speedo is dependant on overall tire diameter not wheel diameter, I just took my 18" winter wheels and tires off my 11 and they are taller than the 20" wheels and tires I use in the summer. I have a couple different scanners I can use to fix the speedo in about 5 minutes.