[WindSSurfer]

I finally got my cable and laptop to function using Freescan. I am now interested in reprogramming with the correct tire size so my speedo will be accurate. I currently have a Herter tune that was installed before I changed to 255-50-17's from the stock size. Before I do this I was wondering how will this affect driveability in terms of trans shift points, fuel etc. Car drives great right now.

Will changing to the correct tire size negatively or possitively affect engine dynamics?

I am assuming that the only way to change the values in the PCM affecting tire size and speedometer reading is by using LT1 edit or Tunercat. Is that correct?

 

[KW Baraka]

.....Will changing to the correct tire size negatively or possitively affect engine dynamics.....

The most profound thing that will happen is that you speedometer and odometer will be exactly correct.

KW