tire recalibration

PALiftedKK · **Posted:** Wed Jan 28, 2015 12:58 pm

just wanted to get some input on the tire recalibrating. my KK had 225/75s on there when I bought the jeep. I currently have on 245/75s on 16s. I took it to Chrysler and the guy said the calibration wouldn't change much. I told him that my speeds were off by 4 mph at the end of the shift range and he just shrugged it off. Im going south again this weekend for 400 miles and the odo will be completely off again if this is not resolved. going an actual 70 mph is a 73 mph on the jeep. Chrysler is ironically the cheapest route to go... $50. so how would I need to convenience him that I need the calibration?

JeepMorrison · **Joined:** Thu Jul 16, 2009 11:34 am **Posts:** 1236

Really 4mph? Mine is 12 mph off.

PALiftedKK · **Posted:** Wed Jan 28, 2015 1:53 pm

yep. 4. glad mines not as bad as yours. but 1 mph off would bother me. I want the odo to be spot on like it was stock. I just think they're being ridiculous, I want to pay them to change a few numbers around. a 5 minute job...

Bmxer524 · **Posted:** Wed Jan 28, 2015 1:56 pm

You'll have less miles on it when it comes time to trade it in or sell it. :jester:

PALiftedKK · **Posted:** Wed Jan 28, 2015 2:03 pm

Bmxer524 wrote:

You'll have less miles on it when it comes time to trade it in or sell it. :jester:

true... I guess ill just reuse my old smart phone for a gps. mileage and speed.

would that change even get me close with an accurate speed?

Scar0 · **Posted:** Wed Jan 28, 2015 3:06 pm

It is out of the dealers hands, because all they can do is select one of the 3 or 4 stock tire size options that are preset in the computer (16,17,18,20). A dealer does not have to option of changing the computer programming.
That is why the tech said it would not make that much of a difference.

EDIT: BTW the 20 is the tallest tire, P245/50R20, 29.65” total diameter, a dealer has the option of selecting.

PALiftedKK · **Posted:** Wed Jan 28, 2015 3:26 pm

Scar0 wrote:

It is out of the dealers hands, because all they can do is select one of the 3 or 4 stock tire size options that are preset in the computer (16,17,18,20). A dealer does not have to option of changing the computer programming.
That is why the tech said it would not make that much of a difference.

EDIT: BTW the 20 is the tallest tire, P245/50R20, 29.65” total diameter, a dealer has the option of selecting.

would it be as simple as taking it to ford and getting them to put in the correct size since Chrysler is unable to? I know ford puts 245 16s on their suvs and trucks.

tommudd · **Posted:** Wed Jan 28, 2015 5:28 pm

PALiftedKK wrote:

yep. 4. glad mines not as bad as yours. but 1 mph off would bother me. I want the odo to be spot on like it was stock. I just think they're being ridiculous, I want to pay them to change a few numbers around. a 5 minute job...

I haven't heard of anyones that was "spot on" from the factory, seems most are off at least 2-3. Mine was off 4 MPH , had it changed for 245-75-16s, then went 265-75-16s and 4.10s, had it set as close as the tech could get it, still 4 off . No big deal in my book

I dare you to take it to Ford and ask them to set it :lol:

Erikg84 · **Posted:** Wed Jan 28, 2015 5:35 pm

tommudd wrote:

I dare you to take it to Ford and ask them to set it :lol:

I double dog dare ya! :POPCORN:

ajohns1288 · **Posted:** Wed Jan 28, 2015 7:35 pm

As said before, the dealer tool only lets you pick from certain values. If you have access to something that can read/write raw data to the OBD port, you can change it yourself, however the ABS module will set a DTC (C1078) if the tire size goes over about 30.25". The hypertechs used to be able to do it, but they removed the feature because it didn't work.

PALiftedKK · **Posted:** Thu Jan 29, 2015 9:21 am

Erikg84 wrote:

tommudd wrote:

I dare you to take it to Ford and ask them to set it :lol:

I double dog dare ya! :POPCORN:

I have 2 ford dealers by me. ill drop them a call at 12 pm. :-)r

JOsworth · **Joined:** Fri Oct 25, 2013 5:40 am **Posts:** 13

Got to hear this...

tire recalibration

Who is online