Advice on tire pressure

[jurko]

I am new to Jeep and off-roading and after a friend of mine took me in her SxS this summer for a couple adventures and I got hooked.
So I bought a 2025 Jeep Wrangler 2 door sport for my 70 birthday in September and love it. Jeep is strictly for off-road use. I also have a VW Golf.

I have access to the south and north of town to the wide open BLM land with many trails stretching for miles within just a few minutes of drive from where I live. I drive on those trails almost daily with my 2 year old Cane Corso running next or behind me and she loves it. I always encounter at least 2 natural springs where she can get a drink which is nice.

After getting 2 flats on OE Nexen Roadian HTX2 (the second one was 4 inch long gash you could put your hand through it) I realized I need A/T tires.
I took a chance on BFGoodrich KO3 but was a little worried due to a lot of negative reviews on BFGoodrich website and other places due to balancing and vibration issues. I ordered them at Discount Tire and had them installed yesterday. I asked the manager if I can observe road force balancing and document the results and he was ok with it.

After I left Discount Tire I went on Hwy and took it up to 80 Mph and the Jeep drove smooth without any vibration at all.

Here's pic with those new tires.

Someone on here posted a link to Tire Pressure Calculator so I entered the info from OE tires and KO3 and this is what I got.

Is that 50 psi recommended for Hwy driving? Discount Tire put 36 psi as stated on a door jamb label.

How much should I air down those KO3's when I am on trail like this?

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[Medsker]

If it were mine I'd run 35 psi on-road and 15 psi off-road. The writing in too small for me to read but 50 psi is way to high on road. Have fun with the new ride!

 

[Ratbert]

Lots of people recommend using a chalk test to figure out what pressure works for your specific combination of tires and vehicle weight. It's pretty simple and should give you a good idea of where it should be.

50 PSI is way too high. You'll probably want to start in the low 30s and work up or down from there.

15-ish is a good starting point for on rocks. Start there until you get comfortable going a little bit lower and depending on obstacle difficulty. I'll usually go to about 12 when doing difficult stuff and (extremely rarely) down to 10 when it's an insane obstacle. Higher when it's primarily for comfort / damage reduction over stupidly long stretches of washboard roads.

 

[dstevens]

50 psi is the pressure used for the maximum load rating. It is not the recommended pressure unless your Jeep weighs 9080 lbs.

 

[jurko]

If it were mine I'd run 35 psi on-road and 15 psi off-road. The writing in too small for me to read but 50 psi is way to high on road. Have fun with the new ride!

Thank you

 

[jurko]

50 psi is the pressure used for the maximum load rating. It is not the recommended pressure unless your Jeep weighs 9080 lbs.

Oh ok, good to know Thanks

 

[jurko]

Lots of people recommend using a chalk test to figure out what pressure works for your specific combination of tires and vehicle weight. It's pretty simple and should give you a good idea of where it should be.

50 PSI is way too high. You'll probably want to start in the low 30s and work up or down from there.

15-ish is a good starting point for on rocks. Start there until you get comfortable going a little bit lower and depending on obstacle difficulty. I'll usually go to about 12 when doing difficult stuff and (extremely rarely) down to 10 when it's an insane obstacle. Higher when it's primarily for comfort / damage reduction over stupidly long stretches of washboard roads.

Good info. Thanks. As far as chalk test - I just rub the chalk on the tire and drive it over black piece of paper and see if the whole width of tread is on paper?

Also I removed rear seats and did muffler delete with AFE pipe which amounted to probably around 100 lbs or more weight off. Because of that, should I run little less Psi in rear tires?

I also visually noticed that there's quite a bit bigger gap between the tire and fender in the rear compare to front. I read on here something about leveling kit which looks like rubber donuts which go on top of front springs to make the gap more even with the rear. Is it something I should consider?

 

[Spacenut]

I have KO2's on a 2 door Rubicon stock and 31 seems to get me the best manners on the road, Almost never gets on the freeway.

 

[Ole_Robby]

14 on that type of terrain.

 

[Blacksport]

Wow...4" long gash in a steel-belted radial? Wondering what you hit...

 

[kah.mun.rah]

A chalk test with my 37x12.5R17 BFG KO2 showed my sweet spot to be around 34 psi on pavement. I air down to 12 psi when off-roading.

 

[jurko]

Wow...4" long gash in a steel-belted radial? Wondering what you hit...

Yeah, I wondered myself but at the time I was so pissed I didn't think to go back and investigate. The problem was that I was going too fast on OE tires on a rocky section of the trail. I got a lot to learn as far as off-roading.

There was another time I looked at my Cane Corso running by my left side and I almost rolled my Jeep over. It scared the shit out of me. I don't have a cell phone so I had to walk 3 hours home and call a couple guys from a local jeep club to help me get out.

 

[Ratbert]

Yeah, I wondered myself but at the time I was so pissed I didn't think to go back and investigate. The problem was that I was going too fast on OE tires on a rocky section of the trail. I got a lot to learn as far as off-roading.

There was another time I looked at my Cane Corso running by my left side and I almost rolled my Jeep over. It scared the shit out of me. I don't have a cell phone so I had to walk 3 hours home and call a couple guys from a local jeep club to help me get out.

You don't have a cell phone????

 

[jurko]

You don't have a cell phone????

No. Just a home phone VOIP from Spectrum.

 

[zouch]

i only see 4 tires on that Result listing; you *did* get all 5 so you'll have a matching spare to get out of wherever you are if you cut up another tire, right?

i typically run Cold PSI in the low-mid 30s on the road depending on conditions; if i see pressures rise more than about 10% in regular use i know my Cold PSI is too low and adjust.

off-pavement i usually start around 12PSI, and will run lower if on Sand or loose Snow.

seeing your last story and knowing the area you're playing in, i'd suggest you might want to investigate a newer cell phone that has Satellite capability for when you're out of Cell coverage. a friend of mine actually used this feature just this weekend when a J**p he rented didn't turn out to be working like it was supposed to (front axle didn't seem to be engaging in 4WD!)

I am new to Jeep and off-roading and after a friend of mine took me in her SxS this summer for a couple adventures and I got hooked.
So I bought a 2025 Jeep Wrangler 2 door sport for my 70 birthday in September and love it. Jeep is strictly for off-road use. I also have a VW Golf.

I have access to the south and north of town to the wide open BLM land with many trails stretching for miles within just a few minutes of drive from where I live. I drive on those trails almost daily with my 2 year old Cane Corso running next or behind me and she loves it. I always encounter at least 2 natural springs where she can get a drink which is nice.

After getting 2 flats on OE Nexen Roadian HTX2 (the second one was 4 inch long gash you could put your hand through it) I realized I need A/T tires.
I took a chance on BFGoodrich KO3 but was a little worried due to a lot of negative reviews on BFGoodrich website and other places due to balancing and vibration issues. I ordered them at Discount Tire and had them installed yesterday. I asked the manager if I can observe road force balancing and document the results and he was ok with it.

After I left Discount Tire I went on Hwy and took it up to 80 Mph and the Jeep drove smooth without any vibration at all.

Here's pic with those new tires.

Someone on here posted a link to Tire Pressure Calculator so I entered the info from OE tires and KO3 and this is what I got.

Is that 50 psi recommended for Hwy driving? Discount Tire put 36 psi as stated on a door jamb label.

How much should I air down those KO3's when I am on trail like this?

Sponsored