Actual height of stock 255\75\17 - Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > JK Jeep Wrangler Forum > JK General Discussion Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 03-02-2012, 03:51 PM   #1
Jeeper
 
pmen14u's Avatar
 
Join Date: Jan 2012
Posts: 21
Actual height of stock 255\75\17

Anyone measure their stock tires, Mine are 30.50" on the jeep, Why I did this was my GPS said one speed and the jeep said another. Checked the tire size calibration and it was set to 30.75". Set the calibration to 30.50" and now both the GPS and the Jeep speed reads the same.. Find it odd they state the 255/75/17's are 32" tall Must have a lot of air in them when they were measured..

Just Saying

pmen14u is offline   Quote
Old 03-02-2012, 03:58 PM   #2
Jeeper
 
JIMBOX's Avatar
 
Join Date: Nov 2009
Posts: 9,914
All tire mfg measure their tires horizontal--

The air pressure/vehicle weight reduces the INSTALLED vertical diameter-

My Hankook LT295/75x16 tire are 33.6" , untill installed, then at 30psi-they're 33.2"

The circumference stays the same, no matter what !

JIMBO

__________________
"ya gotta have class"
JIMBOX is offline   Quote
Old 03-02-2012, 04:03 PM   #3
Jeeper
 
GreenRubi's Avatar
 
Join Date: Jul 2011
Location: Raleigh, NC
Posts: 657
I believe 255/75/17's are supposed to be 32.06" tall prior to mounting and having the weigh of your Jeep on them. Once they are mounted on your wheels and have the weight of your Jeep on them they they are only around 30.75" tall.

At least that is how my 255/75/17 BFG Mud-Terrain T/A KMs are anyways.
__________________
2008 Natural Green JK Rubicon
GreenRubi is offline   Quote
Old 03-02-2012, 04:03 PM   #4
The Bad Guy

WF Supporting Member
 
daggo66's Avatar
 
Join Date: May 2009
Location: NJ exile living in Baltimore
Posts: 22,972
Based on the numbers they are 32". Variables are vehicle weight, PSI, and side wall stiffness. For instance the stock Rubicon tire has a stiffer sidewalk than the Sport S tire.
__________________
Tom

"I've got two things in this world, my balls and my word and I don't break them for no one."
daggo66 is offline   Quote
Old 03-03-2012, 09:05 AM   #5
Jeeper
 
Join Date: Jan 2012
Location: Medford, NJ
Posts: 23
32.06 inches for Goodyear Wranglers
lame is offline   Quote
Old 03-05-2012, 02:30 PM   #6
Jeeper
 
ovrthetop's Avatar
 
Join Date: Nov 2011
Location: Dayton, Ohio, United States
Posts: 122
Jimbo, do you run your Hankooks @ 30 psi? Im still trying to find the sweet spot.. Mine measure just under 33" @ 35psi...
__________________
Cincinnati JKOs join our Facebook group
CJKC
Cincy JK Club - rides only, no BS
ovrthetop is offline   Quote
Old 03-05-2012, 06:57 PM   #7
Jeeper
 
JIMBOX's Avatar
 
Join Date: Nov 2009
Posts: 9,914
I just made a trip back to Calif. and I've got mine at 35psi also-


Quote:
Originally Posted by ovrthetop View Post
Jimbo, do you run your Hankooks @ 30 psi? Im still trying to find the sweet spot.. Mine measure just under 33" @ 35psi...
Usually when I stay in nevada I keep the tires at 32 front/30 rear-

JIMBO
__________________
"ya gotta have class"
JIMBOX is offline   Quote
Old 03-05-2012, 06:59 PM   #8
Jeeper
 
c0d3x5's Avatar
 
Join Date: Dec 2011
Location: summerville, sc
Posts: 314
a good rule of thumb is to take away .75 to 1 inch of what dealer advertises the actual size of their tire..

like jb said.. once tire is at comfortable ride pressures, and weight on top of it.. ur not going to be the same size of the website.. they tend to measure theirs at max pressure with no weight.. makes a big difference.
__________________
Stuff um' and puff um'
33X12.50X17 M/T baja MT w/ 3.73 r-g
17X9 Ultra Nomad Wheels 5" bs
2.5 Teraflex coil spring lift kit w/ exhaust spacer
Coverkings neopreme seat covers
Quadratec floor liners
c0d3x5 is offline   Quote
Old 03-05-2012, 11:31 PM   #9
Jeeper
 
ovrthetop's Avatar
 
Join Date: Nov 2011
Location: Dayton, Ohio, United States
Posts: 122
They are pretty stiff @ 35psi...
__________________
Cincinnati JKOs join our Facebook group
CJKC
Cincy JK Club - rides only, no BS
ovrthetop is offline   Quote
Old 03-05-2012, 11:43 PM   #10
Jeeper
 
JIMBOX's Avatar
 
Join Date: Nov 2009
Posts: 9,914
Can't tell, my jeep rides like a jeep, so They don't feel different to me and/w my shocks-the ride is controlled and "firm" anyway-

JIMBO
__________________
"ya gotta have class"
JIMBOX is offline   Quote
Old 03-05-2012, 11:47 PM   #11
Jeeper
 
ovrthetop's Avatar
 
Join Date: Nov 2011
Location: Dayton, Ohio, United States
Posts: 122
Yeah I'm pretty certain the tires aren't completely to blame... coil spacers and stock susp don't help either ;-)
__________________
Cincinnati JKOs join our Facebook group
CJKC
Cincy JK Club - rides only, no BS
ovrthetop is offline   Quote
Old 05-09-2012, 09:15 PM   #12
Jeeper
 
ThingsAbove's Avatar
 
Join Date: Mar 2012
Location: NC
Posts: 799
I'm curious if stock Rubicon tires are taller than 31" when loaded due to the stiffer sidewall. Has anyone measured their Rubicon front tire height with load on the tires?
ThingsAbove is offline   Quote
Old 05-09-2012, 09:29 PM   #13
Jeeper
 
Slimpickins's Avatar
 
Join Date: Dec 2011
Location: Weeki Wachee, Fl(40miles N of Tampa)
Posts: 430
Quote:
Originally Posted by ThingsAbove
I'm curious if stock Rubicon tires are taller than 31" when loaded due to the stiffer sidewall. Has anyone measured their Rubicon front tire height with load on the tires?
30.75 from the ground up and I am at about 36psi
__________________
A man has to believe in something, I believe I'll have another!
Slimpickins is offline   Quote
Old 05-10-2012, 09:56 AM   #14
Jeeper
 
mgola27's Avatar
 
Join Date: Jul 2010
Posts: 553
I just measured my 255/75R17s.

I copied my post from here http://www.wranglerforum.com/f33/31-...ft-157107.html

Quote:
Originally Posted by mgola27 View Post
I wrapped the masking tape around the center of the tread of my spare (unused, fully inflated), overlapping the tape by a few inches. I then cut the tape through where it overlapped to ensure an accurate length. I measured the length of the tape to find the circumference. From there, I used math to get an actual diameter of my tire.

I came up with 99-15/16" or 99.9375" for the circumference of my unused, properly inflated (35psi) spare.

Using the C = 3.14 * d formula, this is what I've come up with (showing my work per my high school geometry teacher ):

99.9375 = 3.14 * d
99.9375 / 3.14 = d
d = 31.8272

So, I've come to the conclusion that my OE tires, when new have a diameter of 31.8".
Now, I know this changes under the weight of the Jeep, and with different sidewall stiffness, so this may be of no use to you regarding the speedo calibration, but thought I'd share what I found.
mgola27 is offline   Quote
Old 05-10-2012, 01:05 PM   #15
Jeeper
 
pkmcd99's Avatar
 
Join Date: Jan 2012
Posts: 2,117
Quote:
Originally Posted by mgola27
I just measured my 255/75R17s.

I copied my post from here http://www.wranglerforum.com/f33/31-...ft-157107.html

Now, I know this changes under the weight of the Jeep, and with different sidewall stiffness, so this may be of no use to you regarding the speedo calibration, but thought I'd share what I found.
Thats hard on the brain. Just ask next time. OEM tires are known to most as sub 32" treads.....lol.
pkmcd99 is offline   Quote
Old 05-10-2012, 01:45 PM   #16
Jeeper
 
jmcd's Avatar
 
Join Date: Jul 2011
Posts: 195
Are you going to tell him that the speedo and the nav is going to read the same?


Quote:
Originally Posted by JIMBOX View Post
All tire mfg measure their tires horizontal--

The air pressure/vehicle weight reduces the INSTALLED vertical diameter-

My Hankook LT295/75x16 tire are 33.6" , untill installed, then at 30psi-they're 33.2"

The circumference stays the same, no matter what !

JIMBO
__________________
It is not the critic who counts; not the man who points out how the strong man stumbles,The credit belongs to the man who is actually in the arena,whose face is marred by dust and sweat and blood
jmcd is offline   Quote
Old 05-10-2012, 01:49 PM   #17
Jeeper
 
JIMBOX's Avatar
 
Join Date: Nov 2009
Posts: 9,914
Well, if it's the stock-ON BOARD NAV-yes-


Quote:
Originally Posted by jmcd View Post
Are you going to tell him that the speedo and the nav is going to read the same?
I don't know for positive, cause I don't have one, I used my seperate TomTom to double check mine-

JIMBO

__________________
"ya gotta have class"
JIMBOX is offline   Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Cleaning Black stock fender flares ? Beaker541 TJ General Discussion Forum 20 01-25-2014 02:07 PM
Stuffing 35s under a stock JKU Sahara LiftedTj JK General Discussion Forum 8 03-10-2012 02:22 PM
Can't think of one.... mraybrake TJ General Discussion Forum 9 03-05-2012 10:38 AM
Cleaning stock black fender flares ? Beaker541 TJ General Discussion Forum 5 03-02-2012 03:16 PM
Pics of 345/75/16 Km2 anyone. RPN516 JK General Discussion Forum 0 03-02-2012 02:43 PM



Download our Mobile App

» Featured Product

All times are GMT -5. The time now is 09:34 PM.


User Alert System provided by Advanced User Tagging v3.1.0 (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.

Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC