Hello All,
Finally replaced the crappy GY Wrangler A/P's that came on my 98 XLT S/C 4.6 auto 2wd . I went from P255/70r/16's to Cooper P265/75r/16 Discovery A/T's. These tires are 1.5" taller, (31" i believe) how will this bigger tire affect my speedo and mpg??. I read on another thread it would cost 3-4 hundred to have a speed shop recalibrate my speedo. Finally has any one had experience with Cooper tires, the tire shop say's their not as well known as the big3 because their not involved in racing??. Looking forward to your comments.

 

Well your speedo should be off by about 6%. On the 98 model you have a speedo gear on the side of the tranny that you need to change. From what I've heard from other people the difference between your stock reading and your new one is too small to change. You may be able to do something with a superchip but thats like $200. A new gear is only a few dollars. Whoever was feeding you that crap about it being $300 to $400 to adjust the speedo was on crack. I would ignore them in the future if I was you.

 

Lou,

Thanks for the comments regarding Cooper tires in the other thread. Did you notice any performance
loss by going to the bigger tires?

 

When I went from the 255s on my truck to the 265s I noticed a little bit of loss of power but it wasn't too bad. For some reason when I went from the 265s to the 285s it seemed like I had more acceleration but it would downshift alot more when going over hills.

 

Cruzer,

I really haven't noticed any changes other than my odometer is now off 1 mile less for every 10 i drive(there a % in there somewhere) so i assume the speedo is off also.I read that on the 97 & 98's there is a $12 gear you can replace to adjust for tire size. In short i love these tires.





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98 XLT extended cab 4.6 Auto
Magnaflow Dual exhaust
K&N air filter
Covercraft soft tonneo