A little concerned about 5.13 gears with my 37s...
Thread Starter
JK Enthusiast
Joined: Jun 2010
Posts: 142
Likes: 0
From: Battle Creek, MI
A little concerned about 5.13 gears with my 37s...
Checked my actual speed (via GPS) vs my speedometer. I have 3.21 gears. Going to the 37 inch tires leaves my speedo off only about 10-12% (says 45 when GPS says 50). 5.13 gears are a huge jump. I know my speedo will be off the other way... that's not my concern.
My concern is if there's only a 10% difference or so, when I jump 50% in gear ratio, am I going to be burning some super high RPMs?
FWIW, I'm running a 6 speed.
My concern is if there's only a 10% difference or so, when I jump 50% in gear ratio, am I going to be burning some super high RPMs?
FWIW, I'm running a 6 speed.
JK Enthusiast
Joined: Jul 2010
Posts: 401
Likes: 0
From: Williamsport, MD
Checked my actual speed (via GPS) vs my speedometer. I have 3.21 gears. Going to the 37 inch tires leaves my speedo off only about 10-12% (says 45 when GPS says 50). 5.13 gears are a huge jump. I know my speedo will be off the other way... that's not my concern.
My concern is if there's only a 10% difference or so, when I jump 50% in gear ratio, am I going to be burning some super high RPMs?
FWIW, I'm running a 6 speed.
My concern is if there's only a 10% difference or so, when I jump 50% in gear ratio, am I going to be burning some super high RPMs?
FWIW, I'm running a 6 speed.
JK Newbie
Joined: Jan 2011
Posts: 3
Likes: 0
From: St. Johns, Florida
I have a 6 speed manual, 35" KM2's, and am running 5:13 gears. I barely use first gear unless offroad. At 70 mph i am running just under 3000 rpm, and at 75 mph I am running about 3200 rpm. I couldnt be happier
Trending Topics
JK Freak
Joined: Mar 2007
Posts: 709
Likes: 3
From: Frazier Park, CA
X2, 5.13s with 37s are a great combo with a 6 speed.
Check out the gearing info, especially the gear chart in this thread. Starts on post #4.
https://www.jk-forum.com/forums/show...276#post211276
Check out the gearing info, especially the gear chart in this thread. Starts on post #4.
https://www.jk-forum.com/forums/show...276#post211276
JK Super Freak
Joined: Jan 2010
Posts: 1,567
Likes: 0
From: LA CA
Checked my actual speed (via GPS) vs my speedometer. I have 3.21 gears. Going to the 37 inch tires leaves my speedo off only about 10-12% (says 45 when GPS says 50). 5.13 gears are a huge jump. I know my speedo will be off the other way... that's not my concern.
My concern is if there's only a 10% difference or so, when I jump 50% in gear ratio, am I going to be burning some super high RPMs?
FWIW, I'm running a 6 speed.
My concern is if there's only a 10% difference or so, when I jump 50% in gear ratio, am I going to be burning some super high RPMs?
FWIW, I'm running a 6 speed.
JK Enthusiast
Joined: Sep 2010
Posts: 148
Likes: 1
From: Highland, Utah
Had 37's with 4.88 and later 5.38....
just slightly higher RPM between the two, you will likely be happy with both, frankly its hard to tell the difference on the road between 4.88 and 5.38. I notice it mostly offroad where (with the 5.38) in 4lo range RPM are up and speed is lower, sometimes to keep up speed on easier parts of the trail I have to shift into 4 hi.
for me the superchips recalibration made the biggest difference to have everything reset properly, absolutely crazy not to do it
just slightly higher RPM between the two, you will likely be happy with both, frankly its hard to tell the difference on the road between 4.88 and 5.38. I notice it mostly offroad where (with the 5.38) in 4lo range RPM are up and speed is lower, sometimes to keep up speed on easier parts of the trail I have to shift into 4 hi.
for me the superchips recalibration made the biggest difference to have everything reset properly, absolutely crazy not to do it