XR Xtreme Recon and High Tide -- tire pressure lesson learned

[Old Jeeper]

Interesting comments but I am talking about stock 35s on the XR package. No tire change or size change. New Jeep.

Take Away: What is IMPORTANT is the Contact Patch!

You want a full-width contact patch. For several reasons. Safety, traction, braking, and life of the tire. If the outer edges of the tire are not touching pavement then you will prematurely wear out the tire in the center of the tread, if your outer edges wear faster then you are under-inflated.

Your most comfortable ride will come from a full contact patch. If you are off-road in sand, dirt, or rocks you want to max the size of your contact patch.

Look at the design profile of a top off-road tire, like what I run, BFG KM2. 16 in psi in the city give me a FULL-WIDTH contact patch. I run off-road 3-5 psi. My width stays the same but my tire increases the contact patch by getting longer not wider.

Here is a pic of my jeep on 37x1250x17 GY MTRs. That is another purpose-built tire for serious off-roading and in the rocks. I am running about 5-7 psi on GYs. Note the front right tire is bulged out but not contacting the rocks that come from strong sidewalls that support the tire and does not let the sidewall collapse and roll on the rocks.

Now look at the right rear, you get a good idea of how long the tire becomes which increases the contact patch, this is really critical in serious rock trails.

I am running 35s on my 23-JLR, GY Duratrac and I get full contact patch at 32 and they ride like a dream...

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[chicknwaffles]

yeah i'll go ahead and decrease from 35-35. but i'm not going under 30 for street/highway use. don't care what a contact patch is, i'm not comfortable

 

[Fast-n-Furious]

Been daily driving my XR at 33-35 psi. Did a 1000 miles round trip last spring after new, 35-36 psi on highway. Been great.

 

[Old Jeeper]

He was just giving examples of how to ensure you get the correct PSI for the tire/vehicle combo. I personally run mine at about 33psi. They could be lower as they still do not have full contact.

What we have today what was handed to us by the masters but what happens over time is we forget and the tips and tricks or they do not get handed down from father to son and repeat.

Where did I learn contact patch? The Master, my dad who learned it in the 1920s and he taught me in the 1950s. Few people had any idea how much psi to run in their tires, purely hit and miss and most miss than anything else.

If you are reading this, respond to this: How to set the timing on a Chevy V8 engine EXACTLY and keep it that way?

Dad asked me what I wanted for Christmas and said I want a Sun Timing light. Dad looked at me and said, Son, those run about $65 dollars, and they are not that accurate. Come with me.. We go out and he says: Put the car in 2nd gear, pull number 1 spark plug, now I will push on the car and watch the timing wheel and stop it at 12 degrees BTDC. Now loosen the distributor and slowly turn it and go over and hold the number 1 sparkplug in your hand while I turn it.

Next thing I know I am laying on the ground after having been hit with 40,000 volts of spark plug electricity. Dad, why did you do that? Son, you will NEVER forget how to do this. Now tighten down the distributor and you are exactly at 12 degrees and I just saved $65 bucks but I will get you something else.

I doubt what I just wrote has any meaning to 95% of the folks on here. Everything I just said has not been taken over by that computer chip in your car. It does the same thing my dad taught me however only you guys don't find it SHOCKING!

 

[Byrds8]

What we have today what was handed to us by the masters but what happens over time is we forget and the tips and tricks or they do not get handed down from father to son and repeat.

Where did I learn contact patch? The Master, my dad who learned it in the 1920s and he taught me in the 1950s. Few people had any idea how much psi to run in their tires, purely hit and miss and most miss than anything else.

If you are reading this, respond to this: How to set the timing on a Chevy V8 engine EXACTLY and keep it that way?

Dad asked me what I wanted for Christmas and said I want a Sun Timing light. Dad looked at me and said, Son, those run about $65 dollars, and they are not that accurate. Come with me.. We go out and he says: Put the car in 2nd gear, pull number 1 spark plug, now I will push on the car and watch the timing wheel and stop it at 12 degrees BTDC. Now loosen the distributor and slowly turn it and go over and hold the number 1 sparkplug in your hand while I turn it.

Next thing I know I am laying on the ground after having been hit with 40,000 volts of spark plug electricity. Dad, why did you do that? Son, you will NEVER forget how to do this. Now tighten down the distributor and you are exactly at 12 degrees and I just saved $65 bucks but I will get you something else.

I doubt what I just wrote has any meaning to 95% of the folks on here. Everything I just said has not been taken over by that computer chip in your car. It does the same thing my dad taught me however only you guys don't find it SHOCKING!

HAHAHA Now that is funny as hell. I recall setting the timing on my first ride which was a 1979 Camaro. Loved her to death. I remember having a misfire on it and Dad says, "Go out and take the spark plug wires off the cap til the sound doesn't change. When it doesn't change, that is your problem." I asked if I needed special tools he said nah your pliers are fine. So I go out and do exactly what he said because well he's Dad. Same as you, shocked to high hell, arm felt turned inside out and the pliers were across the parking lot. BTW he owned a parts store at the time. I go in and tell him what happens, he laughs his ass off and pulls some plastic pliers from behind the counter and says use this. I asked what they were and he says they were made to remove spark plug wires while running. Im like WTH Dad and he just laughs. Says youll always remember now lol. Damn Dads right? :D

 

[Old Jeeper]

HAHAHA Now that is funny as hell. I recall setting the timing on my first ride which was a 1979 Camaro. Loved her to death. I remember having a misfire on it and Dad says, "Go out and take the spark plug wires off the cap til the sound doesn't change. When it doesn't change, that is your problem." I asked if I needed special tools he said nah your pliers are fine. So I go out and do exactly what he said because well he's Dad. Same as you, shocked to high hell, arm felt turned inside out and the pliers were across the parking lot. BTW he owned a parts store at the time. I go in and tell him what happens, he laughs his ass off and pulls some plastic pliers from behind the counter and says use this. I asked what they were and he says they were made to remove spark plug wires while running. Im like WTH Dad and he just laughs. Says youll always remember now lol. Damn Dads right? :D

LOL, had tears in my eyes, you are the first one outside of myself that Dad has pulled on. Yes times have changed...

 

[Byrds8]

LOL, had tears in my eyes, you are the first one outside of myself that Dad has pulled on. Yes times have changed...

Granted, I will say, that I wish I would have went out and learned more than I did. When I was a kid I hated working on the car with him. I wanted to watch them Saturday morning cartoons. Hind sight being what it is, now, I would loved to had more knowledge. On that same car, he taught me how to line up the fender. At least on that style body/frame. I needed to replace a front fender. After we got one from the junk yard, I got to sand blast it and prime it. Then he tossed it to me and said put it on and walked away. I looked around and was like oh just a few bolts. LOL boy was I wrong. I had three rows across the roof by time I was done. However, when I did get it on, the fender did not line up and I could not open the door. So I go ask him. He was like go loosen this bolt and jack it up then tighten it down. Well, I knew what a frame was and asked how is that gonna help. Well, in no uncertain terms, he said go do what I said. Needless to say I was pissed. I called that man every name under the stars. That is until I was doing what he said and watched in line the fender up LOL. I was astonished then felt bad for all the bad things I called him. He said now Ill never forget. That was 33 years ago.

 

[Old Jeeper]

Granted, I will say, that I wish I would have went out and learned more than I did. When I was a kid I hated working on the car with him. I wanted to watch them Saturday morning cartoons. Hind sight being what it is, now, I would loved to had more knowledge. On that same car, he taught me how to line up the fender. At least on that style body/frame. I needed to replace a front fender. After we got one from the junk yard, I got to sand blast it and prime it. Then he tossed it to me and said put it on and walked away. I looked around and was like oh just a few bolts. LOL boy was I wrong. I had three rows across the roof by time I was done. However, when I did get it on, the fender did not line up and I could not open the door. So I go ask him. He was like go loosen this bolt and jack it up then tighten it down. Well, I knew what a frame was and asked how is that gonna help. Well, in no uncertain terms, he said go do what I said. Needless to say I was pissed. I called that man every name under the stars. That is until I was doing what he said and watched in line the fender up LOL. I was astonished then felt bad for all the bad things I called him. He said now Ill never forget. That was 33 years ago.

A GOOD Dad is one mean SOB you cuss till the day comes you leave out on your own and about a week later you come to know Dad was the smartest man in the room.

 

[Byrds8]

Damn straight. He is 76 now and I still call from time to time to ask advise. :D

 

[Viking Jeeper]

Interesting comments but I am talking about stock 35s on the XR package. No tire change or size change. New Jeep.

My 392 with 285/75/17 indicated 37 psi so with 35's it should be lower. How much lower can be argued forever.

 

[dcmdon]

Interesting comments but I am talking about stock 35s on the XR package. No tire change or size change. New Jeep.

I have a Gladiator with XR take offs and run them at 31 psi, they are perfect.
Do the math on 1/2 mpg less fuel economy. It works out to like $30/yr.

When I picked up my truck, then with 33s on it, Gupton had aired them up to 37 psi per MFG recommendations.

Within 20 miles temps and pressures were up to about 40 psi. I pulled over and aired them down to 34. (hot, so about 31 cold). That worked well.

I have used the same pressure with my larger XR tires and its great. I could try to go lower, but haven't gotten around to it.

For what its worth, I bought this inflater/gauge and its awesome. Its funny, the tires are so even that both fronts go up in the TPMS system within a minute of each other as they warm up. Same for the rears.

Also nice is that when its disconnected from the air hose, it can be used as a gauge.

Finally, the connector to the tire stem is AMAZING. This is its best feature. Put it on and it doesn't leak a drop of air. NONE!!! Hands free. And it comes off super easy.

I can't recommend this thing highly enough. Its worth it just for the connector.

https://smile.amazon.com/gp/product/B01ETWXEWA

 

[Apexcars]

I run 30 psi in the factory tires. Chalk test says I could go a little lower but 30 gives me some room as tires lose pressure between air ups.

 

[Old Jeeper]

I have a Gladiator with XR take offs and run them at 31 psi, they are perfect.
Do the math on 1/2 mpg less fuel economy. It works out to like $30/yr.

When I picked up my truck, then with 33s on it, Gupton had aired them up to 37 psi per MFG recommendations.

Within 20 miles temps and pressures were up to about 40 psi. I pulled over and aired them down to 34. (hot, so about 31 cold). That worked well.

I have used the same pressure with my larger XR tires and its great. I could try to go lower, but haven't gotten around to it.

For what its worth, I bought this inflater/gauge and its awesome. Its funny, the tires are so even that both fronts go up in the TPMS system within a minute of each other as they warm up. Same for the rears.

Also nice is that when its disconnected from the air hose, it can be used as a gauge.

Finally, the connector to the tire stem is AMAZING. This is its best feature. Put it on and it doesn't leaks a drop of air. NONE!!! Hands free. And it comes off super easy.

I can't recommend this thing highly enough. Its worth it just for the connector.

https://smile.amazon.com/gp/product/B01ETWXEWA

https://www.amazon.com/gp/product/B01ETWXEWA?pldnSite=1

Thanks, ordered!

 

[dcmdon]

https://www.amazon.com/gp/product/B01ETWXEWA?pldnSite=1

Thanks, ordered!

You are welcome.

It reads in half psi increments. so to get them all EXACTLY the same, and I realize its ridiculous to do, but I kind of just wanted to see if I could do it.

I would run the tire up to 32 psi. then let air out with the bleeder in 3 second increments until I got to 31.5. Then I would tap the bleeder for 1 second and read until it showed 31.

I did that on all 4 and its essentially the same.

Yes, over kill and stupid. I realize that.

 

[Byrds8]

Maybe Ill drop mine a bit more to get closer to full contact. Even at 33, I am not hitting about an inch or so on both sides of the stock tires. I think the most I have seen mine heat to is 35 when its in the 70s.

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