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Discussion Starter #1
so maybe its my OCD but I would like my tires to have the same PSI level. I ordered new rims / tires put them on yesterday. Look awesome however they are aired all over the place. One tire has 48 PSI another has 39PSI.

The max load (cold) says 65PSI

should I add air to the three tires ranging from 39 to 42 PSI of should I just let some air out of the tire thats 48PSI? this is an everyday driver so no rock crawling for me anytime soon.

Thanks.
 

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Not sure which tires but 28-32 is probably where the best range is for most Jeeps and for pavement. Many run E rated tires like the Toyo MTs at 26 psi. Your pressures seem way too high.
 

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yup 26-28 seem to be the best for street, tire shops are retarded for the most part when it comes to air pressure
 

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Discussion Starter #4
thanks guys I thought so. I don't know what they were thinking. its like they went out for a smoke break when they aired up the tire thats at 48PSI lol. I am going to make them all like 32PSI or something.
 

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Tire shops are mainly following what these manufactures are stating for the rule economy or CAFE requirements. The tire pressures used to be normal- around 30-32 for most vehicles (not heavy trucks that tow). Now they are all getting closer to 40. I find that pressure dangerous on light vehicles. Traction is reduced and the ride blows. Even my Jeep tech buddy says they have to go by stated PSI when talking to customers but none of them run their personal vehicles that high.

Also, keep in mind that E rated tires are designed for vehicle that tow (full-size trucks and other heavy vehicles). They do need thicker tread plies and more air pressure for their weight and especially when towing trailers, fifth wheels, etc..
 

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The guy I bought my jeep from had put brand new street tires on it, and they were at FIFTY pounds and the ride sucked.

I put the 315s on and played around with the pressure, I've been around 32 for months and happy with it, not too soft, not too hard.


.
 

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With that whole Firestone/Ford Explorer thing from the late 90's, retailers and shops really don't stray much from the door placard recommendation. I sell tires and recommend door placard pressures all the time to nearly everyone, but my Jeep gets 32psi in the 315/70-17s and I know I'd be just as safe in the 26psi range, but I like the slight bump in gas mileage with 32psi personally.
 

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The sise of your tires make me suspect, even one tire can bare the GAWR of the most loaded axle even, so a low pressure can be save.
But being D-load with AT pressure of 65 psi mayby even one tire can bare the whole car fully loaded, so even lower pressure is possible.

But a D-load tire needs more pressure for the same load then a P-tire with its 35 psi AT-pressure( wich is not the maximum pressure written on P-tires).

Other thing is that you probably have ofroad or ofroad-looking tires that have large profile blocks that cover a part of the sidewall, ( to my conclusion the case at the Firestone tires for the Ford Explorer in the Ford/Firestone-affaire), the same as the Jeep from the picture above this forum.
These profile blocks leave less deflection allowed for the sidewall wich leads to lower maximum load to carry then is written on sidewall. Estimated that you have to substract up to 20% of the maximum load given on sidewall.

Googled your sises but could not be shure about the loadkind.
Found Loadindex 127 .
Googled again and put LRD behind sises and gave LI 121 , so this LI is already for LT tire.
LRE gave LI 127 so these ofroad tires are only in LT and not in P-tire in the market.

So if your tires are the ofroadkind as in the picture above this forum , substact first 20% or substact 8 LI steps so LI 113/1150kg/2535lbs.
This still justifies a pressure of about 1/3th of AT pressure of yours 65 psi.
=about 22 psi. This because of your total weight of probably 3500lbs .

So to make this already to long story short, give me as acurate determined seperate wheelweights , second best axle-weights, other Gross axle weight ratings ( GAWR) and GVWR ( V for Vehicle) and maximum speed you wont go over for even a minute in your use.

Then from Tires sidewall read
1. maximum load or Loadindex,
2. AT-pressure ( already known 65 psi) and
3. speedcode of tire.
Also give an idea of the profile blocks to determine the substraction of maximum load I explained.

Then I will put these data in my made motorhome tirepressure calculator ( can also be used for this) and give a picture of it in my answering post.

Greatings from a Dutch pigheaded self-declared tire-pressure-specialist.
 

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Discussion Starter #11
The sise of your tires make me suspect, even one tire can bare the GAWR of the most loaded axle even, so a low pressure can be save.
But being D-load with AT pressure of 65 psi mayby even one tire can bare the whole car fully loaded, so even lower pressure is possible.

But a D-load tire needs more pressure for the same load then a P-tire with its 35 psi AT-pressure( wich is not the maximum pressure written on P-tires).

Other thing is that you probably have ofroad or ofroad-looking tires that have large profile blocks that cover a part of the sidewall, ( to my conclusion the case at the Firestone tires for the Ford Explorer in the Ford/Firestone-affaire), the same as the Jeep from the picture above this forum.
These profile blocks leave less deflection allowed for the sidewall wich leads to lower maximum load to carry then is written on sidewall. Estimated that you have to substract up to 20% of the maximum load given on sidewall.

Googled your sises but could not be shure about the loadkind.
Found Loadindex 127 .
Googled again and put LRD behind sises and gave LI 121 , so this LI is already for LT tire.
LRE gave LI 127 so these ofroad tires are only in LT and not in P-tire in the market.

So if your tires are the ofroadkind as in the picture above this forum , substact first 20% or substact 8 LI steps so LI 113/1150kg/2535lbs.
This still justifies a pressure of about 1/3th of AT pressure of yours 65 psi.
=about 22 psi. This because of your total weight of probably 3500lbs .

So to make this already to long story short, give me as acurate determined seperate wheelweights , second best axle-weights, other Gross axle weight ratings ( GAWR) and GVWR ( V for Vehicle) and maximum speed you wont go over for even a minute in your use.

Then from Tires sidewall read
1. maximum load or Loadindex,
2. AT-pressure ( already known 65 psi) and
3. speedcode of tire.
Also give an idea of the profile blocks to determine the substraction of maximum load I explained.

Then I will put these data in my made motorhome tirepressure calculator ( can also be used for this) and give a picture of it in my answering post.

Greatings from a Dutch pigheaded self-declared tire-pressure-specialist.
wow that was very detailed dutch. Thanks I will look into that have a good one.
 
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