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View Full Version : Tires and computer reset?



HydroTech
03-04-2005, 09:01 AM
I recently put bigger tires on the KJ. I just went from the crappy stock goodyears which were 215's to size 235. So, still stock but just a little bigger. Anyway, do I need to get the computer tweeked by the dealer to compensate for the larger tire size?

I have heard that the computer has three settings for tire size: 215's,235's and then an "other" category.

OverkillZJ
03-04-2005, 11:19 AM
I have no idea, I don't know the first thing about a KJ :)

HydroTech
03-04-2005, 11:47 AM
8O

Bill
03-04-2005, 01:17 PM
I have no idea, I don't know the first thing about a KJ :)

x2 :roll:

HydroTech
03-04-2005, 02:47 PM
Matt did you have any issues with this on your Grand? Just wondered.

OverkillZJ
03-04-2005, 02:55 PM
Matt did you have any issues with this on your Grand? Just wondered.

I don't know, is my rig even still a grand? ;)

When it was still my dads, he went up 1.3" in tire size with everything else stock without a problem. Maybe there is a comptuer setting in the KJ's, but my bet is that it's just to calcualte the mileage and speed correctly. This is a total guess of course!

With the 35's my gearing compensated for the tire size, so other than breaks, I'm driving on stock tires as far as the engine / tranny are concerned

HydroTech
03-04-2005, 03:03 PM
Ya that is what I figured as well. I am taking it in for inspection and thought since I am there I would have them set the computer accordingly.

For some reason though, I thougt I read on the LOST KJ board that MPG was affected by this. Can't remember.

Thanks for the info!

dp
03-04-2005, 07:25 PM
It's not going to matter really. The only problem I've heard was actually only in Dakotas running super big tires and their trannies not shifting right.

The only thing is your speedo will be a bit off. And as far as I know, you cannot just go into the PCM and change your tire size -- you have to flash the whole thing and download all new software. It's really not worth it (that is if it is possible that way at all) -- I was a Ford guy.