Kanybam

I just got my 08 lifted and put 18 in rims with 33in tires on. Anyone know how much work is entailed in getting the spedometer/odometer adjusted so that it's not off? I got a speeding ticket the first night I picked it up from the shop because I completely forgot that it would be off. Cop says I was doing 78 in a 55 when I thought I was only doing 65. $150 ticket after just spending $3200 on lift, rims, and tires!! :(

Goose

That sucks! Sorry to hear about your luck.

I do know that the dealer can re-flash your ECU to adjust for a larger tire size, but I believe the largest size they can go to is a 32".

Hypertech, one of the forum sponsors, makes a hookup that will allow you to re-flash your ECU for, I believe, up to a 37" tire. May want to check them out.

https://www.jk-forum.com/forums/sponsor-list-87/performance-miscellaneous-accessories-22262/

Fifth sponsor down on this ^ page.

davidwm71

Dealership may be able to do it for 33s. If you had 225/75r16 and went to 33s your speedometer is off by about 13% from the actual speed. At 78 your speedometer should have said you were doing 68. At 50 your only going to be about 6 mph off. Still better to fix it for proper odometer readings and so you don't have to calculate your speed whenever driving.

You could also buy a programmer and do it... with the programmer you could change other setting too.

pearl-drum-man

Everything I've seen is that the dealer will only do it up to the largest stock size, which is essentialy a 32". I'm not sure why they can't/won't do additional sizes though.

spencenaz

HA! Sounds like the speedo being off is not the only problem Mr. Leadfoot.!

The dealer won't help you here. They will only go up to 32" The pro-comp or hypertech programmers allow you to change you computers tires size. That is your best bet.

j&k'sjk

That sounds like a big difference in your speedo. I went to 33/17's on my unlimited and checked the speedo against my gps and was only under by .8 mph. i am not worried about mine.

ESPMike

Thats some bad Jeep karma there sir!


I bought the AccuPro which is the programer Hypertech makes. Its a bit pricey at $200, but well worth the money. It will get your speedo and odometer DEAD ON, it will read and clear diagnostic codes, and it also helps set automatic tranny shirt points if you have an auto. Granted you wont use it much, but even as the tires wear the speedo will fall off a bit, so this way you can just reflash it whenever you feel the need at home. VERY easy to use, literally idiot proof, and fast too. Worth the 200 bones.

Kanybam

thanks for all the replies. I hadn't thought about by not adjusting it, the odometer would show less mileage. Good point. And yes, my leadfoot also lead to the ticket.

PhirstJeep

That does seem very high! With my 33s, I'm seeing a 2mph difference (checked my speedo against my GPS at 40, 50, 55, 60 and 65mph...all 2 mph difference.

ESPMike

Sounds good, until the Jeep Gods get there revenge! Nothing but cracked windshield and broken axels for you! Haha, just kidding man.