I went to 35" tires on my 05. When I have the computer reset for the correct revolutions this should correct the speedo. and milage. I have 3. 73 gears. It feels like the truck bogs down and needs to shift to a lower gear sometimes. This can't be good for the trans. When I have the dealer reset the revs. per mile will this change the shift points for a better down shift at the right time. Are there any pros or cons in having this done. My mpg will not be good with 35" tires may have to go to 33". Thanks for the help!