My speedometer is off about 6 mph after going to 33's. Does the change in tire size also impact the odometer reading. In other words, am I recording more or less miles on the odometer than I would if I was properly calibrated?

Also, are there programmers specifically for calibration of the speed? So far the normal programmer options are not 2011 compatible.

 

I have a '10 with 35's and I was wondering the same thing. Mine is about 5mph off according to my Nuvi GPS.

So what your saying is that when we travel 60 miles the odometer is actually going up by 54 miles? If this is true and you go through one set of tires at about 30K miles then your odometer is off by like 3,000 miles. If this is true you get about 3,600 extra miles on your bumper to bumper warranty and 10,000 on your Power Train!!! Sweet!!!

 

Yes your odometer is also off. If you have a gps.. zero them both out and drive for awhile. Also if your speedometer is off if you watch your GPS and its speed it is telling you it will also be off more the faster your driving. Mine is off by 3-4 at 25ish when im going 70 its off by 6-7 according to gps.

 

go here to see the difference in speed between stock and new:

http://www.discounttiredirect.com/di...foTireMath.jsp

Some dealers will flash your Jeep control module n/c other charge and may not always get it right. SuperChips, Procal and probably others will allow you to set your tire size.

Use a GPS to make sure it's correct. I have 35" tires and had to set my SC to 33.5" to get speedo correct.

 

X2 on this

 

Yup plus its giving you a false (lower) mpg because of the odometer being off by 10-15%

 

As questioned by another post in this thread.. You mean it odometer is going to register less miles than I have actually traveled?

Yes, it is by my GPS display that I know I am off by about 6mph.. The speedometer is registering 55 and the GPS display says 61 mph.

I asked my dealer to calibrate it as best they could and they looked at me like I had three heads...

SuperChip (and all the other performance programmers) aren't 2011 compatible.. Procal doesn't do performance changes, right?



hmmm....interesting.. so the drop in mpg isn't entirely because of the lift and removing the air dam?

 

The Procal will adjust the tire size which will also affect the auto trans shift points which make it feel more "stock". Manual trans no performance difference.

 

Yes your odometer will reflex less mileage then the jeep has actually travel... So yes you could lie about odometer reading (don't recommend it), reason I never buy my jeeps or trucks prelifted with oversized tires.

 

AEV Procal and your problems are solved, plus you'll get a lot of other benefits as well. Best money you'll spend.