BFG KM2 air pressure - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Wrangler Forums > JK Wrangler Technical Forum > BFG KM2 air pressure

Light up the holidays with LED lights from JeepHutIntroducing MONSTALINER™ UV Permanent DIY Roll On Bed LineRuffstuff Axle Simple Swap Kit!

Reply
Unread 10-06-2009, 09:21 PM   #1
AJ in Japan
Jeeps and Bikes - Yea!
2007 JK Wrangler 
 
Join Date: Oct 2007
Location: Japan
Posts: 257
BFG KM2 air pressure

Hey gang,

I just lifted my 2D JK and put 35/12.50/18 KM2s on the stock rims (painted the spokes black). I am waiting on 1.5" spacers from Quadratech. When I picked it up from the dealer it felt really light in the steering (much to my surprise). They had 40 psi in the tires. By searching here I have found most running 26 to 28 psi. That seems a little low. What say you?

Thanks!

__________________
AJ in Japan
2007 2-Door Sahara in Black - "Sarah"
2004 Vulcan 2000 - "The Dude"

Mods:

3.5” Skyjacker lift / Currie adjustable control arms (all 8) / Skyjacker dual steering stabilizer /
Poly Performance front and rear track bar relocation kits RHD / Poly Performance high steer kit with drag link flip adapter / 35/12.50/18 BFG Mud Terrain tires on stock painted rims with 1.5” Spidertrax wheel spacers / 5.13 Superior Gears front and rear /gear ratio, tire size and 91 octane performance adjusted with Superchips controller / ARB differential covers / Skid Row front skid plate / Mopar undercarriage skid plates (stock in Japan) / Mopar Rock Crawler bumpers front and rear with rear tire carrier / High Lift Jack mounted on rear bumper (when off roading) / Smittybuilt black D-Rings front and rear / Rampage Products Convertible Side Bar/Rocker Guards / AEV Heat Reduction Hood with AEV Snorkel / 1” over fender extensions / KC running lights on windshield and front bumper / Stubby antenna in black/ Warrior Products Mirror Relocation Brackets when doors are off / Meiwa Ultra Performance Muffler / B & M transmission cooler / Quadratec Ultimate Front Floor Liners / Off Road Heroes Soft Top / Daystar Hood latches and spare tire bump stops / Glass lens headlights with H-4 bulbs (stock in Japan) – headlight and fog bulbs changed to Sylvania Silverstars / Off Road guards for headlights, fog lights and tail lights / MS Plus Navigation System / rear seat removed (1st mod) / and other stuff I can’t remember now

Next: Change the junk Skyjacker Nitro shocks to Bilstein 5100s (on back order now per Dave at Northridge) and change the junk Skyjacker sway bar disconnects to JKS.


http://share.shutterfly.com/action/w...8AcOGjlq3YtGLj

http://www.vroc.org/view_profile.php?user_id=998

http://rogueownersgroup.com/MemberPage.aspx?id=10

Doing it on the left side in Kanazawa, Ishikawa Japan.

Riding a motorcycle is the only time in my existence when I can completely lose myself only to find myself.

It's not the destination.........

It's the ride!
AJ in Japan is offline   Reply With Quote Quick reply to this message
Unread 10-06-2009, 10:06 PM   #2
WVUJeeper
Registered User
2008 JK Wrangler 
 
Join Date: May 2008
Location: Denver, CO
Posts: 1,247
I run mine at 30-32 psi...15 offroad.
__________________
- Fletcher: Oil Field Trash Extraordinaire
Quote:
Originally Posted by VetteDriver View Post
BTW, what's with the "if you haven't driven one shut up" nonsense? How can we have a good internet fight if experience and knowledge are going to be a requirement?
'08 Rescue Green Unlimited X - Hard Top, 3.73 gears, Limited Slip, Infinity 7 speaker system, KC Slimlite Long Range, Cobra CB, Rough Country 2.5" BB, 35" BFG KM2's on ProComp 7089's. Fenderless and proud!

My build thread: HERE

RESCUE GREEN JEEP CLUB MEMBER #25
COLORADO JEEP CLUB MEMBER # 1001
WVUJeeper is offline   Reply With Quote Quick reply to this message
Unread 10-07-2009, 07:45 AM   #3
Woodchuck
Senior Member
 
Woodchuck's Avatar
2008 JK Wrangler 
 
Join Date: Mar 2008
Location: Oklahoma City
Posts: 801
I have 35" KM2's but mine are 17". I run right around 30psi for normal driving around town and about 15psi offroad and all is well. Anything over 30 and you can really start to feel the bumps and much less and you get a litle squirelly(sp). I do inflate them to 35psi if I am gonna run on the highway for a long time (more than an hour) like on road trips an such.
__________________
'08 Red Rock Unlimited Rubicon / AEV 2.75" Lift with Remote Reservoir Shocks / AEV Heat Reduction Hood / AEV Front & Rear Bumper with Tire Carrier / AEV Skidplates & Rear Corner Guards / Riddler Diff Covers / Mopar Enhanced Rock Rails / Warn 9.5ti Winch / Mopar Gas Cap Cover / 4.88 Gears / IPF 900xs Drive Beams / Eagle Eye HID Spotlights / Daniel Stern Headlights / 17" AEV Pintler Wheels with 35x12.5r17 BFG Mud-Terrain KM2's / Tuffy Security Drawer / sPod and Benchmark Dual Battery System / Cobra 75 CB / Lockpick with Front and Rear Cameras / Katzkin Heated Seats / Line-X Interior / Hitchsafe Key Vault / and a Trasharoo and a lot more little stuff or just stuff I forgot!!!

____oooo
[ l_,[____],
l---L -[OlllllllO-
( )_) ( )_)-o-)_)
Woodchuck is offline   Reply With Quote Quick reply to this message
Unread 10-07-2009, 07:59 AM   #4
warCryr
Registered User
2008 JK Wrangler 
 
Join Date: Dec 2008
Location: Holland, Michigan
Posts: 206
maybe im over-inflated, I feel sewer lids like they're speed bumps..
__________________
2008 JK
4.88, 6spd, RK 2.5", 17x8 Cragar Soft 8s, 33" BFG KM2s, JKS trackbars, RR breather kit, K&N, cowl snorkel, Benchmark bumpers, Tuffy interior, Riddler diffs
warCryr is offline   Reply With Quote Quick reply to this message
Unread 10-07-2009, 09:06 AM   #5
N2rock
Registered User
2007 JK Wrangler 
 
Join Date: Jul 2007
Location: Sugar Land, TX
Posts: 7,078
I run mine 28-29psi street, and 10psi wheeling.

The shop that installed them put them at 40psi- that made for a very rough ride home At 29psi, they absorb a lot of the road bumps and make for a much smoother ride.

When traveling I usually bump them up to 35psi to help with my terrible gas mileage
__________________
for details and info on our JK's, check out http://n2rock.com

His: '07 Unlimited X, Jeep Green, Hardtop, auto, 5.13, 2.5" RC lift and too many mods to list

Hers: '08 X Red Rock, soft top, auto. Bunch of mods

Quote:
Originally Posted by tlgraham View Post
If you made a snuggy out of a Shamwow, ....would you have to get up off the couch to pee?
Quote:
Originally Posted by Deepskyy View Post
At this point if Obama tried to move a little to the right, he would trip over Stalin's corpse.
N2rock is offline   Reply With Quote Quick reply to this message
Unread 10-07-2009, 09:44 PM   #6
robsbluerub
Registered User
2007 JK Wrangler 
 
Join Date: Dec 2006
Location: Lynchburg, VA
Posts: 273
34-36 psi = best gas mileage

28-30 psi = best ride and tire wear

I run 30 psi. I love these tires. they're quiter that the original muds and better on wet pavement, excellent offroad.
__________________
2007 JK 2dr Rubicon, 3" Black Diamond Lift, 35" KM2s, M/T Classic IIs, Rancho shocks, Mopar bumpers, 8000 lb winch, Ace rock sliders, Skid Row engine/oil pan skid, evap skid, Tom Woods driveshafts, Riddler diff covers, rear adjustable upper control arms, chromoly rear shafts, Reid knuckles, Synergy chromoly tie rod, track bar, and flipped drag link.
robsbluerub is offline   Reply With Quote Quick reply to this message
Unread 10-07-2009, 10:06 PM   #7
FatBuoy
Registered User
 
Join Date: Dec 2007
Location: Austin
Posts: 1,017
Quote:
Originally Posted by robsbluerub View Post
34-36 psi = best gas mileage

28-30 psi = best ride and tire wear

I run 30 psi. I love these tires. they're quiter that the original muds and better on wet pavement, excellent offroad.
Ditto for me
__________________
Black Rubi JKU with a rompin' stompin' 6.1 magnuson supercharged hemi!
FatBuoy is offline   Reply With Quote Quick reply to this message
Unread 10-07-2009, 10:23 PM   #8
BrettDez
Registered User
2012 JK Wrangler 
 
Join Date: Apr 2007
Location: Niagara County, NY
Posts: 1,343
Best way to find the pressure is to take the time to do the chalk test. Your pressure is dependent on the weight of your vehicle too, those with heavy armor/bumpers/winches/other gear added can make a difference in pressure.

Take your tires, inflate them to 30psi as a starting point. Then take some thick sidewalk chalk and draw a line accross the tread horizontally. Then observe the wear in the chalk you drew.

If the chalk wears off evenly, then it is a good pressure.

If the chalk wears out in the center faster, then you are overinflated, let some out and try again.

If the chalk wears out on the outside faster, then you are underinflated, add some more pressure and try again.
__________________
-Brett
-----------------------------------------------------------------------------
My Jeep: 2012 Jeep Wrangler Unlimited Rubicon, 6-Spd Manual, Cosmos Blue
"The Smurf": --Pic 1-- --Pic 2-- --Pic 3-- --Pic 4--
Previous Jeeps: --2007 Jeep Wrangler JK Rubicon-- --2003 Jeep Wrangler TJ Rubicon-- --1987 Jeep Wrangler YJ--
BrettDez is offline   Reply With Quote Quick reply to this message
Unread 10-11-2009, 08:11 AM   #9
1398653
Registered User
2004 TJ Wrangler 
 
Join Date: Jan 2009
Location: Olean NY, New York
Posts: 1,121
I dropped my 255/75-17 BF Goodrich KM's to 30 from 37 that the shop put in. The Ride is so much better around town. The TPMS is going off though. Is there a way to reprogram this to accept 30 psi as normal?
__________________
Steve, Olean NY, 2004 TJ Rubicon & 2006 LJ Unlimited
1398653 is offline   Reply With Quote Quick reply to this message
Unread 10-11-2009, 08:46 AM   #10
N2rock
Registered User
2007 JK Wrangler 
 
Join Date: Jul 2007
Location: Sugar Land, TX
Posts: 7,078
Quote:
Originally Posted by 1398653 View Post
I dropped my 255/75-17 BF Goodrich KM's to 30 from 37 that the shop put in. The Ride is so much better around town. The TPMS is going off though. Is there a way to reprogram this to accept 30 psi as normal?
Yes- You need a programmer. There are a variety of them available. The AEV Procal is the least expensive- it will allow you to program in the any threshold you want from zero psi on up, and has a number of other helpful features.
__________________
for details and info on our JK's, check out http://n2rock.com

His: '07 Unlimited X, Jeep Green, Hardtop, auto, 5.13, 2.5" RC lift and too many mods to list

Hers: '08 X Red Rock, soft top, auto. Bunch of mods

Quote:
Originally Posted by tlgraham View Post
If you made a snuggy out of a Shamwow, ....would you have to get up off the couch to pee?
Quote:
Originally Posted by Deepskyy View Post
At this point if Obama tried to move a little to the right, he would trip over Stalin's corpse.
N2rock is offline   Reply With Quote Quick reply to this message
Unread 10-11-2009, 09:06 AM   #11
1398653
Registered User
2004 TJ Wrangler 
 
Join Date: Jan 2009
Location: Olean NY, New York
Posts: 1,121
Quote:
Originally Posted by N2rock View Post
Yes- You need a programmer. There are a variety of them available. The AEV Procal is the least expensive- it will allow you to program in the any threshold you want from zero psi on up, and has a number of other helpful features.
Would it be cheaper to have the dealer do it?
__________________
Steve, Olean NY, 2004 TJ Rubicon & 2006 LJ Unlimited
1398653 is offline   Reply With Quote Quick reply to this message
Unread 10-11-2009, 09:21 AM   #12
N2rock
Registered User
2007 JK Wrangler 
 
Join Date: Jul 2007
Location: Sugar Land, TX
Posts: 7,078
Quote:
Originally Posted by 1398653 View Post
Would it be cheaper to have the dealer do it?
I don't think dealers will do it because that it technically altering a safety mechanism. So I think their hands are tied when it comes to TPMS. The Procal is relatively cheap ($130), and has enough other features to make it worth the price.
__________________
for details and info on our JK's, check out http://n2rock.com

His: '07 Unlimited X, Jeep Green, Hardtop, auto, 5.13, 2.5" RC lift and too many mods to list

Hers: '08 X Red Rock, soft top, auto. Bunch of mods

Quote:
Originally Posted by tlgraham View Post
If you made a snuggy out of a Shamwow, ....would you have to get up off the couch to pee?
Quote:
Originally Posted by Deepskyy View Post
At this point if Obama tried to move a little to the right, he would trip over Stalin's corpse.
N2rock is offline   Reply With Quote Quick reply to this message
Unread 10-11-2009, 04:38 PM   #13
LHS-Cowboy
DETN8R
 
LHS-Cowboy's Avatar
2008 JK Wrangler 
 
Join Date: Jul 2007
Location: Fort Worth, Texas
Posts: 605
I hate it, but I have to run 21 psi to get best tire wear. I up the shock stiffness to try and counter act it some. 37x12.50x15 MTR's.
__________________
'08 DETN8R Yellow Unlimited Rubi
6-Spd / Soft top / Power

Installed:
R.E. Modified 3.5 Super Flex Kit to 4+/Ft. & Rr. U-joint driveshafts/Full Traction Rear Adj. Trackbar/Custom Ft. Heim Joint Adj. Trackbar/Rancho 9000XL shocks/Yukon 4.88 Gears & Superior Rear Axle Shafts/37" Pitt Bull Rockers on Custom Allied Beadlocks/Poly Perf. Rock Sliders/Shrockworks Mid Ft. & Rear Bumper/Custom Trans. Crossmember and Skid/Custom High Steer with PSC Hydro Assist/Plumbed Warn PowerPlant HP/Cobra 75 WS XT C.B./Bully Dog Programmer/Custom Exhaust/Dual Optimas/48" X-treme Hi-Lift Jack on Custom Rear Swing Away Carrier/...

____oooo
[ l_,[____],
l---L -[
OlllllllO]
( )_) ( )_)--)_)
LHS-Cowboy is offline   Reply With Quote Quick reply to this message
Unread 10-11-2009, 04:41 PM   #14
Hellbound13
Registered User
2008 JK Wrangler 
 
Join Date: Mar 2008
Location: New York
Posts: 1,500
Quote:
Originally Posted by LHS-Cowboy View Post
I hate it, but I have to run 21 psi to get best tire wear. I up the shock stiffness to try and counter act it some. 37x12.50x15 MTR's.
What is wrong with the ride at 21?
Hellbound13 is offline   Reply With Quote Quick reply to this message
Unread 10-12-2009, 05:17 AM   #15
LHS-Cowboy
DETN8R
 
LHS-Cowboy's Avatar
2008 JK Wrangler 
 
Join Date: Jul 2007
Location: Fort Worth, Texas
Posts: 605
excess body roll, sidewall stiffness, etc.
__________________
'08 DETN8R Yellow Unlimited Rubi
6-Spd / Soft top / Power

Installed:
R.E. Modified 3.5 Super Flex Kit to 4+/Ft. & Rr. U-joint driveshafts/Full Traction Rear Adj. Trackbar/Custom Ft. Heim Joint Adj. Trackbar/Rancho 9000XL shocks/Yukon 4.88 Gears & Superior Rear Axle Shafts/37" Pitt Bull Rockers on Custom Allied Beadlocks/Poly Perf. Rock Sliders/Shrockworks Mid Ft. & Rear Bumper/Custom Trans. Crossmember and Skid/Custom High Steer with PSC Hydro Assist/Plumbed Warn PowerPlant HP/Cobra 75 WS XT C.B./Bully Dog Programmer/Custom Exhaust/Dual Optimas/48" X-treme Hi-Lift Jack on Custom Rear Swing Away Carrier/...

____oooo
[ l_,[____],
l---L -[
OlllllllO]
( )_) ( )_)--)_)
LHS-Cowboy is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.