Tire Pressures

[Guinea]

So my 2014 1500 currently has 4 Cooper tires on it, and before this it had Michelin Tires (mightve misspelled the name). I've been having this issue where even though all 4 are at the manufacturer specified 39 psi cold, the middle of the rear tires always wears out and they're once again almost bald. I've tried lowering this latest set to 35 psi in the rear, still 39 in the front, but it doesn't seem to change the rear tires wearing down quickly in the middle. Is this an overinflation issue or something deeper? Should I only have them at 39psi when under an almost full load? If so what should I keep them at? And is there a way in the computer to set the new tire pressure lower so the TPMS light doesn't come on everytime I start the vehicle? Thanks in advance for your help!

 

[Ridgerunner665]

Tire size and wheel size?

Thinking maybe the tire is too wide for the wheel.

 

[RLJ10X]

Center tire wear is usually over inflation. But your pressures aren't that high.

 

[indept]

The factory pressures are too high IF the bed is unloaded.
Do the chalk test to determine correct pressure.
https://www.youtube.com/watch?v=W0qL20nBNRI

 

[Guinea]

The factory pressures are too high IF the bed is unloaded.
Do the chalk test to determine correct pressure.
https://www.youtube.com/watch?v=W0qL20nBNRI

Wow alright, thanks so much I'm gonna do this immediately after getting a full set of 4 new ones. This was super helpful!

 

[Guinea]

Tire size and wheel size?

Thinking maybe the tire is too wide for the wheel.

The wheel is P275/60r20 and the tires are M+S 275/60R20. I'm not sure if the different letters in the beginning could be an issue, but the shop I got the tires put on at didn't say anything about it.

 

[Rlaf75]

How many miles on the set of tires? I ran with 40psi in my 2011 Ram quad cab all the time and got nearly 40k miles out of the stock goodyear tires. I rotated them between 5 and 10k miles and they wore perfectly fine. Now with my brand new 21 I'm still running 40psi in the tires and they still look good at 1500 miles

 

[Guinea]

How many miles on the set of tires? I ran with 40psi in my 2011 Ram quad cab all the time and got nearly 40k miles out of the stock goodyear tires. I rotated them between 5 and 10k miles and they wore perfectly fine

These have just over 20k and are going bald at the moment. I definietly need new tires unless I wanna be skiing around with my truck instead of driving in the winter lol. My theory is that the factory pressure might only be good for a loaded bed, so I should decrease the pressure on the new tires I get to ensure the tires are fully contacting the road surface

 

[Rlaf75]

These have just over 20k and are going bald at the moment. I definietly need new tires unless I wanna be skiing around with my truck instead of driving in the winter lol. My theory is that the factory pressure might only be good for a loaded bed, so I should decrease the pressure on the new tires I get to ensure the tires are fully contacting the road surface

I dont know what your driving and maintenance habits are but I tow a 7x11 enclosed trailer every so often but everyday driving the bed is empty and I still ran 40 psi. Rotation is key. Like i said i rotated the tire every 5 to 10k miles. You say the tires have 20k miles, have you rotated them at all in those miles

 

[Bigskyroadglide]

My Cooper at3s are at 30k, never been rotated and are like new. I run 40psi. One year old by dot date code.

This is on 2011 quad cab 5.7 hemi.

I tow 7x14.

Maybe you got an older set of tires.

My Goodyear SRAs on my 14, are doing exactly what you indicated. They are at 35 psi.

35 k on tires. No load, RCSB. That experiences spirited driving

They are 5 years old and are wearing quickly

 

[Phirebeard]

The wheel is P275/60r20 and the tires are M+S 275/60R20. I'm not sure if the different letters in the beginning could be an issue, but the shop I got the tires put on at didn't say anything about it.

The P is for P-metric, ie standard load rating as opposed to heavy duty load range ie 6,8,10 ply (C,D,E load). M+S is mud and snow rated, ie all-season.

 

[heckcat9]

You can use AlphaOBD to change your TPMS thresholds.

Chalk test is probably the easiest way to figure out your pressures, as already mentioned.

A good starting point can be determined by using your Gross Axle Weight Rating (GAWR) and your specific tire's maximum load and maximum pressure rating.

TirePressure = [ ( GAWR / 2 ) / MaxTireLoad ] × MaxTirePressure

For example, I run Cooper SST Pros in 37x12.5R20 at the moment.
Gross weight rating per tire = GAWR / 2 = 1950
3750 max load @ 65 PSI
Pressure ratio = 1950 / 3750 = 0.52
Tire pressure = 0.52 × 65 = ~34 PSI
I started at 34 and based on wear found that 31 PSI with the truck unloaded is the sweet spot for daily driving. Your numbers will of course be different.

 

[CamperMike]

Maybe I missed it, but are you rotating the tires? If not, try that! The rears will wear more in the middle, front more on the sides. If you rotate, it should even them out reasonably well. Also I do run a few PSI lower on rears when unloaded, but still rotate occasionally to wear them evenly.

 

[indept]

Wow alright, thanks so much I'm gonna do this immediately after getting a full set of 4 new ones. This was super helpful!

Be sure to do the test when the tires are warm. Do both front & back. I found that my fronts are fine at 39 psi and my backs like 35 psi . you can get the real big chalk at walmart in the toy section.
Cheers

 

[DURASPANK]

Sounds like to many burnouts, Do have a kid that drives your truck also?

 

[62Blazer]

The wheel is P275/60r20 and the tires are M+S 275/60R20. I'm not sure if the different letters in the beginning could be an issue, but the shop I got the tires put on at didn't say anything about it.

That is not the wheel size (the wheel being the steel or aluminum center or rim). Both numbers stated above are tire sizes. The rim would be 20" diameter and a certain width, and if stock I think there was only one width of 20" rims. Typically a rim size is expressed something along the lines of 20x9, which is 20" diameter and 9" width. The P and M+S listed above would describe two tires of the same size, with the difference being one was a "passenger car" rated and the other a mud + snow rated tire.
Based on the description of the tire wear typically the center part of the tread wearing faster indicates the pressure being too high. However on these lighter tires with only 40 psi it's typically not much of an issue. You usually see that type of wear on people running heavier duty D and E rated tires where they have 65-80 psi in the tires.

 

[indept]

Based on the description of the tire wear typically the center part of the tread wearing faster indicates the pressure being too high. However on these lighter tires with only 40 psi it's typically not much of an issue. You usually see that type of wear on people running heavier duty D and E rated tires where they have 65-80 psi in the tires.

Not so. My factory SRA's wore like that in the rear. I always kept them at the stickers 39 psi. Rotating helps but it's not a fix just a bandaid. Running the rears at regular pressure (with no real load in the bed) wears the center which means your rear tires only have partial tread to road contact which could cause you to spin out on curves etc. So doing the chalk test and adjusting pressure for full contact not only helps with premature tire wear, it's safer too.

 

[Irishthreeper]

How many miles on the set of tires? I ran with 40psi in my 2011 Ram quad cab all the time and got nearly 40k miles out of the stock goodyear tires. I rotated them between 5 and 10k miles and they wore perfectly fine. Now with my brand new 21 I'm still running 40psi in the tires and they still look good at 1500 miles

So my 2014 1500 currently has 4 Cooper tires on it, and before this it had Michelin Tires (mightve misspelled the name). I've been having this issue where even though all 4 are at the manufacturer specified 39 psi cold, the middle of the rear tires always wears out and they're once again almost bald. I've tried lowering this latest set to 35 psi in the rear, still 39 in the front, but it doesn't seem to change the rear tires wearing down quickly in the middle. Is this an overinflation issue or something deeper? Should I only have them at 39psi when under an almost full load? If so what should I keep them at? And is there a way in the computer to set the new tire pressure lower so the TPMS light doesn't come on everytime I start the vehicle? Thanks in advance for your help!

39 lbs is not an over inflation issue but two sets of different tires doing the same thing means something is awry. I’d try to figure it out before paying for new tires.
Not related but my ‘21 2500 calls for 60 front and 65 rear. It felt funny when I drove it home from the dealership and discovered they had over 80 lbs in each tire!

 

[stormcom]

Sounds like a misaplication of the gas pedal. If you keep your foot out of it, the tires may last a little longer. Also, make sure you don't have your foot on the brake when you take off.

Just a little humor. I only run LTX's on mine at 37 psi. Works great.

 

[gto64gto]

I had a 2010 1500 crew cab 2 wd and now have a 2017 1500 4 wd. Both had 20 inch factory rims. I swithh tires ever 5000 miles and have a tread depth gauge that I check the tread depth several places while I move tires. It will tell you the tread depth all across the tire. I do not hall any weight. I have found the factory pressure is too high. I run 38 psi in front and 35 psi in rear. The tread wear is perfect. I got 54000 miles on my tires that came on my truck when I bought it new. Hope this helps someone. BTW, my 2019 RT Charger call for 32 psi all the way around and my tires on it wear perfect too.