4.88 vs 5.38 with 34's (285/75R17) Auto JKU
01-19-2012, 03:47 PM
#21
JK Freak
Join Date: Jun 2011
Location: Clearwater, Florida
Posts: 693
Likes: 0
Received 0 Likes
on
0 Posts
first off, 34's is not a common size and i would steer you away from them just for that. if you're looking at 285's, that would be the better way to go. having said that, 5.38 is WAY OVER THE TOP for the size tire you are looking at. 4.88 will be plenty fine and, so long as you make sure to calibrate your speedo, you will not have the shifting issues you've apparently read about.
01-20-2012, 11:30 AM
#24
JK Enthusiast
Join Date: Jul 2011
Location: Kansas city,MO
Posts: 337
Likes: 0
Received 0 Likes
on
0 Posts
first off, 34's is not a common size and i would steer you away from them just for that. if you're looking at 285's, that would be the better way to go. having said that, 5.38 is WAY OVER THE TOP for the size tire you are looking at. 4.88 will be plenty fine and, so long as you make sure to calibrate your speedo, you will not have the shifting issues you've apparently read about.
01-20-2012, 11:54 AM
#25
JK Newbie
Join Date: Jul 2011
Location: Conway,AR
Posts: 39
Likes: 0
Received 0 Likes
on
0 Posts
I guess I am confused, my speedometer is already re-calibrated for my 35in tires, but how will that help me change my shift points and not run at 1500rpms on the interstate doing 70 constantly downshifting. I guess I don't know all the functions I can do with it.
01-20-2012, 12:12 PM
#26
JK Freak
Join Date: Feb 2010
Location: Porterville, CA
Posts: 550
Likes: 0
Received 0 Likes
on
0 Posts
Why are you stuck because it is a 2011. You don't need a "tuner" to recalibrate the PCM, a recalibration module will take care of the calibration issues but not add any HP/torque. I am running 5.38 gears in my 2011 and purchased the AEV Procal to recalibrate my PCM to compensate for gear ratio and tire sizes. Runs like a champ and everything shifts great.
At 70 MPH it is running right at 2500 RPM down the interstate. This is with 35" KM2s measuring 33.75" in height.
Personally I am glad I didn't go with the 5.13 gears which I was originally considering. I am very pleased with the decision to go with the 5.38.
Mike.
At 70 MPH it is running right at 2500 RPM down the interstate. This is with 35" KM2s measuring 33.75" in height.
Personally I am glad I didn't go with the 5.13 gears which I was originally considering. I am very pleased with the decision to go with the 5.38.
Mike.