By on 5th August 2020

How to Calibrate Jeeps Speedometer and Odometer

For bigger tyres 32″ BF Goodrich Mud Terrain KM

For the Jeep Grand Cherokee WK or Commander XK 2005-2010, or practically all Jeeps since 2005. JK, JL, JT, WK2, KK, MK. Plus all Chrysler models, plus all Dodge models and all Ram models. How to calibrate the speedometer and odometer, trip recorder etc for bigger tyres. This will even do Export models as well, like the WH, XH that have bigger tyres 255/75/17. Watch the whole video below, as the last bit is the screen grabbed exact DETAIL part.

Finally been able to do this been waiting 3 years! I used the Vgate adaptor, the OBD JScan Android app and my Android phone, for a cost of £30 in around 2 minutes. That’s after being told by countless tecchies, that this could not be done on a WH Export model! It can!! Jeep WK – WH speedo wheel tire size height correction or tyre calibration from 29.5″ tyres to 32″.

Plus I now have a single VIN licence for other tweaks that I may need to do to my Jeep in the future. It will go up to 40 inch tyres. Change your tyre size to 32″ and your speedo will be approx 10% out. This is how to correct the setting. It takes 2 minutes and costs £30 or $35 for the all equipment and tools needed plus your phone.

 

The testing

After doing this I drove 169 miles to test it out. With a revised tyre size setting made at 32 inches, the following results were observed. Cross checking my journeys with Google maps showed my Jeep had only covered 166 miles. So the calibation is around 1.8% out on distance travelled. This is what gives you gas or fuel mileage or economy measure. So not bad. The speedometer is close to stock, where at a shown speed of 65mph, you are actually going 61mph. This is normal.

Common wheel heights for Jeeps

235/65R17 – 29.02 tall
245/65R17 – 29.5″ tall
265/70R17 – 31.6″ tall
255/75R17 – 32.06″ tall
285/70R17 – 32.7″ tall
285/75R17 – 33.83″ tall

 

How I did it for my Jeep

 

OBD JScan Jeep App

OBD JScan Jeep App

OBD JScan Jeep App

OBD JScan Jeep App

OBD JScan Jeep App

OBD JScan Jeep App