zouch

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hey, Phil,

bunch o' things here.

first, sorry; i thought i saw you say somewhere your tires were D rated.

next; variance from labelled sizes is a given that's well beaten to death, and not worth further discussion.
but if we're talking about products and specs, those labelled tire sizes are what we have to go by, since (as you're aware) the specs for a manufacturers 315/70s are not necessarily the same as the specs for their 35' tire; they're different tires.

starting with the basics.
Cold Tire Pressure means the pressure of the tire after it has been sitting unused out of the sun and at ambient air temps for at least 2-3 hours. setting your tire pressure under any other conditions is not going to give you relevant repeatable results.
there are allowances for when airing back up when tires are warm that allow ~4PSI above the target pressure. (there's even mention of this in your Users Manual).

i'm not familiar with any TPMS alert like what you describe; maybe it's a Willys vs Rubicon thing, but i don't see anything like that in the Users Manual outside of the Low Tire Pressure warning that's supposed to come on when you're significantly low on pressure.
i've never seen the Low Tire Pressure Alert come on except when aired down significantly and *not* in 4WD.

i've never seen a "Do Not Exceed" pressure listed on a tire. can we get a pic of that? (maybe it's a Toyo thing?)

TPMS alert ranges are adjustable beyond what the dealer may be willing/able to do for you. i see it mentioned as a feature in the Tazer manual; i'm not sure if there are other tools available that will do it. you might look into something like one of those if after verifying pressures your situation continues and you want to stop ignoring those warnings and make them actually helpful again.

for your case, i'd make damn sure i had an accurate gauge (or 3), check the tires in the morning before the sun hits them and they're the same temp as the air around them, and fill them to 35 (as that's your tire manufacturers max). after that i'd be honestly surprised to see the pressures rise much more than 10% in use unless there are changes in temperature or altitude unless your rig is loaded to a point past what those tires are rated for. (again, surprisingly, the Users Manual actually has some decent discussion on compensations for Temperature and Altitude.)
i would expect to find that 30-31 Cold is too low.


I have C rated Toyo R/Ts. Yes, they are the 31570R17 not 35x12.50. Neither of those tires is 35" though. They are less than half an each apart from each other and the 305 is a tenth of an inch from 34" so I just feel like its easier to say 35" rather than 31570R17. If you look at a different tire from the same manufacturer, like the open country M/Ts, and the 31570R17 is a different diameter anyway.

The TPMS alert in the dash is what I am referring to that is "telling me". It is set to 37 PSI from the factory so it wants me to inflate over my max PSI. Dealer told me they cannot adjust it.

The PSI range on them is greater than 10% cold to hot. Even if I am not driving them, if I check them in the early morning and in the afternoon just sitting it will move about 10%. Even on the stock 33" tires inflated to 37 PSI cold it would move more than 10% when driving. Right now my "cold" PSI is around 30-31 depending on the temp in the morning and after a long drive at highway speeds will hit about 36 (which just so happens to be the threshold to turn off the TPMS alert). If I haven't driven it all day but check it in the afternoon, it might be 33-34 range. I have also in the past set them to 35 PSI cold and they will get up to 40 PSI after a long highway drive which I think is listed on the tire as the "never to exceed" pressure. My current approach is to air up to 35 PSI after wheeling and then they later cool down overnight to about that 30-31 range I mentioned before. I do even notice a difference in PSI based on which tires are in the sun vs the shade.

I've mostly just decided to not worry about it too much and enjoy the vehicle, but I was curious to see what the stock XR PSIs were.
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PSUdaemon

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Phil
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hey, Phil,

bunch o' things here.

first, sorry; i thought i saw you say somewhere your tires were D rated.

next; variance from labelled sizes is a given that's well beaten to death, and not worth further discussion.
but if we're talking about products and specs, those labelled tire sizes are what we have to go by, since (as you're aware) the specs for a manufacturers 315/70s are not necessarily the same as the specs for their 35' tire; they're different tires.

starting with the basics.
Cold Tire Pressure means the pressure of the tire after it has been sitting unused out of the sun and at ambient air temps for at least 2-3 hours. setting your tire pressure under any other conditions is not going to give you relevant repeatable results.
there are allowances for when airing back up when tires are warm that allow ~4PSI above the target pressure. (there's even mention of this in your Users Manual).

i'm not familiar with any TPMS alert like what you describe; maybe it's a Willys vs Rubicon thing, but i don't see anything like that in the Users Manual outside of the Low Tire Pressure warning that's supposed to come on when you're significantly low on pressure.
i've never seen the Low Tire Pressure Alert come on except when aired down significantly and *not* in 4WD.

i've never seen a "Do Not Exceed" pressure listed on a tire. can we get a pic of that? (maybe it's a Toyo thing?)

TPMS alert ranges are adjustable beyond what the dealer may be willing/able to do for you. i see it mentioned as a feature in the Tazer manual; i'm not sure if there are other tools available that will do it. you might look into something like one of those if after verifying pressures your situation continues and you want to stop ignoring those warnings and make them actually helpful again.

for your case, i'd make damn sure i had an accurate gauge (or 3), check the tires in the morning before the sun hits them and they're the same temp as the air around them, and fill them to 35 (as that's your tire manufacturers max). after that i'd be honestly surprised to see the pressures rise much more than 10% in use unless there are changes in temperature or altitude unless your rig is loaded to a point past what those tires are rated for. (again, surprisingly, the Users Manual actually has some decent discussion on compensations for Temperature and Altitude.)
i would expect to find that 30-31 Cold is too low.
I just went and checked. It's ~63F outside here in Denver a little after noon and all 4 tires are reading 34 PSI by the TPMS sensors.

I was going to get you a picture of the alert, but it's not currently showing. It's in the TPMS screen and it says something to the effect of "inflate your tires to 37 PSI" and some of the individual tire pressures are yellow if it thinks that particular tire is low. It won't go away until all 4 are above a certain level. This coincides with the low tire pressure light. In addition, I am 99% sure this also happens when i am in 4 low. It seems to trigger when the tires are somewhere below 30 PSI and then resets when they get above 35 PSI. It's tracks each tire individually, so I can have one tire showing as white at 34 PSI and one tire as yellow (low) at 35 PSI because it hasn't hit the reset threshold. I don't think my tires go under 30 PSI, but I get this issue when I first start driving where the PSI reading from the TPMS sensor drops ~3 PSI and then jumps back up less than a minute later. It wouldn't be a problem if my tires were closer to 37 PSI, but as I said I usually set them close to 35 PSI and then in the cold morning they are 30-31. By cold morning, I mean 30s F.

So I think the "do not exceed" thing I may have misunderstood. That's not the entire text. In full it reads "Do not exceed 40 PSI when seating bead." So maybe that really doesn't apply to warm tire temps.

I am aware of Tazer and other products that can change that TPMS threshold, however I have been avoiding anything that might upset the warranty gods. Right now the alert is just an annoyance. I do intend to get one of them eventually after the warranty is gone. I didn't pay for the extended one.

As far as temp and altitude go, I am all over the place. I live in Denver, and I wheel in the mountains, so I am often over 10k ft. Even the trail heads are often near those altitudes so that's where I air up and then drive back to Denver. And of course the temp can vary wildly between those areas. In Denver alone the temps can frequently swing 40 degrees from morning to afternoon. I don't daily this Jeep. At most I run some occasional errands around town in it. Most of the miles are to and from the trails. So most of the miles are actually going up and down between ~5k and ~13k ft. I'll take a look at the manual and see what it says about altitude.
 

DZLJLUR

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DJ
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No idea, I’ve never run it. The dual rate springs should help the sag issue when loaded that was a major issue on our rubicon when it was stock. The shocks are better quality than the stock shocks, but I cant speak to their valving. They are also longer than stock so flex would be improved as well.
Thanks Zack!
 

JustDave

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I think you are the minority. Dozens of aftermarket flares, and I can’t think of a single one that is wider than stock. If there was sufficient demand, there would be aftermarket wide flares. Any wider and dot would require clearance lights like the raptor, trx, and duallies run.
Clearly you don't live in PA. Law says can't have tires sticking out & they nail you for it. That's the reason i have lame ass stock width tires on my JL
 

JustDave

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The DV8 ones wouldn't look so bad with the appropriate wheels and tires to fill them out. Definitely look ridiculous on stock sport or Sahara wheels and tires. A set of 37×13.50's with more offset wheels and those fenders would look pretty good.
I would love to see some pics of that setup. I'd buy them in a minute if they filled them out.
 

razorbc

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2021 Rubicon 1984 CJ7 Laredo
My XR in the same setup is on the rails. Should be here in less than 2 weeks

Sting Grey
XR Package
Tow
Gorilla Glass
Leather
8.4 stereo
remote
 

Carbonalpine

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Makes me excited for my ‘22 XR
 

graytrucks

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As promised, more pics now that its daylight, and steps installed…
DE2D57B6-0A6F-4A0C-A9C2-925AD4ADEA59.jpeg
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178F374C-DD77-47A0-AFAC-CFC8576E6734.jpeg
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2D247840-EA8E-4FF8-A130-DBF9CCB15F76.jpeg
Your Jeep looks great! I am looking at those same N-Fab steps for my Sting Gray, are you happy with them so far? My kids want something to help with my 37s. Do they help reduce flying rocks and debris at all? I’d love to cut down on rock chips and messy fender flares. Thanks
 

Jtphoto

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Jeff
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Thunder Bay ON
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2018 Wrangler JKU Rubicon / Xtreme Recon on order
Depending how and where you wheel they may be a liability. I’ve run them on my JKU for 4 years with no issues. But we don’t have rocks here like out west.
 

Carbonalpine

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I just ordered my AMP power steps, jumped the gun because AMP themselves told me to wait until their engineering team can verify the 2022's fitment/wiring.

Side note, I have those N-Fab steps on my JKU and they don't hold up well. I don't wheel it, I go to light trails/mudding...but they rust in some spots. I still have them and plasti dip the spots like a lazy a$$ every so often
 
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