If you change tyre diameter you have to insert the new revs per mile to the jeep's computer. This is for a 2004 with DRBIII, 2005 uses CAN bus so you have to check if this is needed and how it is done... However, I am sending you the link for the DRBIII procedure
https://colorado4wheel.com/content/drb_KJ_speedo.html
100km/h, 4th gear (gearing 4.10, 245/75R16)-> 2000rev/min
100km/h, 4th gear (gearing 3.73, 245/75R16)-> 1800rev/min
100km/h, 4th gear (gearing 3.73, 235/70R16)-> 1875rev/min
You can calculate it if you know the transmission ratio, transfer case ratio, gearing ratio, and tyre rotations per km.
I have made an excel document for this. If you want it sent me a PM
https://colorado4wheel.com/content/drb_KJ_speedo.html
100km/h, 4th gear (gearing 4.10, 245/75R16)-> 2000rev/min
100km/h, 4th gear (gearing 3.73, 245/75R16)-> 1800rev/min
100km/h, 4th gear (gearing 3.73, 235/70R16)-> 1875rev/min
You can calculate it if you know the transmission ratio, transfer case ratio, gearing ratio, and tyre rotations per km.
I have made an excel document for this. If you want it sent me a PM
