Tire P.S.I?

[6.7CumminsDrvr]

42 psi in my e range 35’s.

tire inflation table is your friend.......where do you think the manufacture derive their recommendations from? The load inflation table will show what minimum psi is required to support a given weight and you adjust from there for ride quality and wear.


As info, I’ll take some of the work out of the equation: stock Goodyear’s have a capacity of 2,365 lbs, not 2,601.

whatever size tire you run, find out what psi will support 2,365 lbs and go from there.

if you really want to know the absolute minimum psi you can run, scale your truck to determine the actual weight and then go from that.......

 

[boblonben]

2020 RAM Crew Cab Pathfinder A/T 275/556/20. Running 38 lbs front and rear. Good ride, great handling, good balance for overall use of truck. cheers

 

[corneileous]

42 psi in my e range 35’s.

tire inflation table is your friend.......where do you think the manufacture derive their recommendations from? The load inflation table will show what minimum psi is required to support a given weight and you adjust from there for ride quality and wear.


As info, I’ll take some of the work out of the equation: stock Goodyear’s have a capacity of 2,365 lbs, not 2,601.

whatever size tire you run, find out what psi will support 2,365 lbs and go from there.

if you really want to know the absolute minimum psi you can run, scale your truck to determine the actual weight and then go from that.......

Well, if you call up GoodYear, Michelin and toyo like I did a while back, they’ll all argue with you and tell you that for like the SRA’s for example, if they’re stamped at 2,601 pounds at 44 psi, they will safely support 2,601 pounds at that pressure, period. That 2,601 pounds stamped on the sidewalls is not there for decoration. Does that mean you can load the back of your truck up to where there is 5,200 pounds pushing down on your rear tires? No, that’s not what that means; well, it could if your payload capacity, suspension, wheels, axle and frame can hold that much but that just means that your tires together at that pressure will support that much weight.

But before an argument breaks out over it… again.... who knows, maybe that’s how the truck manufacturers come up with X amount of psi which like on our trucks for example, 39 pounds of pressure it’s probably all we will ever need to safely support whatever our trucks can support but airing them to the max stamped pressure should certainly help towards stability.


Sent from my iPhone using Tapatalk

 

[EdGs]

Funny, when you look up the crap-year sr-a tires, the chart doesn't list 40 psi for the 113 tires.

Wouldn't suprise me if I was looking at it wrong, either.

I put a set of LT265/70R17 Cooper Discoverer A/T from Wal-Mart on mine (I think they are A/T3's though, just slightly changed for WM). They are a E range, 121/118S.

Keep them about 50 psi.

 

[6.7CumminsDrvr]

Well, if you call up GoodYear, Michelin and toyo like I did a while back, they’ll all argue with you and tell you that for like the SRA’s for example, if they’re stamped at 2,601 pounds at 44 psi, they will safely support 2,601 pounds at that pressure, period. That 2,601 pounds stamped on the sidewalls is not there for decoration. Does that mean you can load the back of your truck up to where there is 5,200 pounds pushing down on your rear tires? No, that’s not what that means; well, it could if your payload capacity, suspension, wheels, axle and frame can hold that much but that just means that your tires together at that pressure will support that much weight.

But before an argument breaks out over it… again.... who knows, maybe that’s how the truck manufacturers come up with X amount of psi which like on our trucks for example, 39 pounds of pressure it’s probably all we will ever need to safely support whatever our trucks can support but airing them to the max stamped pressure should certainly help towards stability.


Sent from my iPhone using Tapatalk

when a p rated tire is used in a light truck application, it’s load rating is reduced by a factor of 1.1.

This comes from the FMVSS...



Exert from load inflation table:




So yes, the stock Goodyear has a capacity of 2,601 lbs but in the case of our trucks, It’s derated by 1.1 which equals 2,365 lbs.

 

[corneileous]

Funny, when you look up the crap-year sr-a tires, the chart doesn't list 40 psi for the 113 tires.

Wouldn't suprise me if I was looking at it wrong, either.

I put a set of LT265/70R17 Cooper Discoverer A/T from Wal-Mart on mine (I think they are A/T3's though, just slightly changed for WM). They are a E range, 121/118S.

Keep them about 50 psi.

View attachment 239550

Go to any dealership and look at a brand new truck. Look at the sidewalls on the tires. Now, I’m not sure at all about the tires they use for the trucks that also come factory equipped with the 22 inch wheels but if you find one that has the same stock 20’s with the 275/60 GoodYear SRA’s wrapped around them that were the standard for over the last ten years, they all say 2,601 pounds at 44psi. I guarantee you. The stock tires that came on my 2018 Limited 1500 were exactly the same as the stock tires that were still on my 2008 Ram 1500 when I bought it used in December of 2012.


Sent from my iPhone using Tapatalk

 

[corneileous]

when a p rated tire is used in a light truck application, it’s load rating is reduced by a factor of 1.1.

This comes from the FMVSS...



Exert from load inflation table:

View attachment 239554


So yes, the stock Goodyear has a capacity of 2,601 lbs but in the case of our trucks, It’s derated by 1.1 which equals 2,365 lbs.

Fine, then you call up GoodYear, Michelin, Toyo or whatever other tire brand you want and ask them all the same thing. Either you’ll be surprised yourself or who knows, maybe you’ll be better at interpreting what they all told me whenever somebody brings up this **** about p rated tires being somehow magically derated as soon as you put them on a large SUV or pickup but whenever I asked that, they didn’t know what I was talking about. Acted like they never heard of such a thing and one of the tire manufacturers I talked to, I believe it might’ve been toyo, they said that **** you’re talking about only apples when you put a LT tire in place of a p rated tire but one thing the ALL said was if the damn tire says it will support a certain weight at a certain pressure then it will do EXACTLY that.

But who knows, in my probably inaccurate opinion, they probably only say that that you’re saying is so that people don’t automatically assume that they can now load their trucks or SUVs up to what their tires can hold at max pressure since the vehicle they’re mounted to can’t which is why I think the number of 2365 pounds is all you need because the truck won’t safely support more than that but whatever, the tires themselves don’t change.


Sent from my iPhone using Tapatalk

 

[EdGs]

Go to any dealership and look at a brand new truck. Look at the sidewalls on the tires. Now, I’m not sure at all about the tires they use for the trucks that also come factory equipped with the 22 inch wheels but if you find one that has the same stock 20’s with the 275/60 GoodYear SRA’s wrapped around them that were the standard for over the last ten years, they all say 2,601 pounds at 44psi. I guarantee you. The stock tires that came on my 2018 Limited 1500 were exactly the same as the stock tires that were still on my 2008 Ram 1500 when I bought it used in December of 2012.

I hear you, and they are marked like that, but the on-line charts look as if they don't recommend them to be run at 40 psi.

My truck was alway squirrelly in the ass-end with the sr-a's, though. They seemed to wear OK, at least mine did.

 

[corneileous]

when a p rated tire is used in a light truck application, it’s load rating is reduced by a factor of 1.1.

This comes from the FMVSS...



Exert from load inflation table:

View attachment 239554


So yes, the stock Goodyear has a capacity of 2,601 lbs but in the case of our trucks, It’s derated by 1.1 which equals 2,365 lbs.

I know I’ve already quoted this post once before but the only reason why I’m even bothering to quote it a second time is because I just got off the phone with my local discount tire and started talking to him about this and I quoted to him everything that you said in this post above and even he even said and even he’s never heard anything about a tire being magically derated from its capacity when it’s put on a certain vehicle so once again, this 1.1 stuff must mean something else totally different or apply to something else because even he himself said that when a manufacturer puts a tire on their vehicles brand new and they say that that tire must be inflated to that pressure, that only means that that’s all the pressure that that tire needs to have in it to support the weight that the truck can only handle. Hell, who knows, maybe that is what you, and and so many other people have been trying to say all along but just got a ****** way of explaining it.


Sent from my iPhone using Tapatalk

 

[corneileous]

I hear you, and they are marked like that, but the on-line charts look as if they don't recommend them to be run at 40 psi.

My truck was alway squirrelly in the ass-end with the sr-a's, though. They seemed to wear OK, at least mine did.

What chart, the one that CumminsDrVr posted, or are we talking about some other chart? But without knowing what this other chart is, if what you say is the case then why would the tire manufacturers be allowed to put something on a tire that wasn’t true? Sure seems to me that if these tires really weren’t able to be inflated past 40 psi they’d be facing like lawsuits left and right if anybody ever blew one out.

But I’m curious; when you said the back end your truck was squirrley with the SRA‘s, how heavy were you pulling and what did you have the tires inflated to? I mean, at least I can understand partially why somebody would want an eight ply or 10 ply truck tire on their truck if they were pulling really heavy all the time but in all seriousness, if you inflate those SRA‘s to their max pressure, I just can’t see how sacrificing your ride quality is worth it on that heavy-built of tires but again, I guess that’s just me.

So far, I’ve yet to haul anything really heavy on my new Michelin‘s that are pretty much the same thing as the SRA’s but I guarantee you if I ever do, I will be inflating them to their maximum pressure and I betcha I’ll be just fine.


Sent from my iPhone using Tapatalk

 

[EdGs]

What chart, the one that CumminsDrVr posted, or are we talking about some other chart? But without knowing what this other chart is, if what you say is the case then why would the tire manufacturers be allowed to put something on a tire that wasn’t true? Sure seems to me that if these tires really weren’t able to be inflated past 40 psi they’d be facing like lawsuits left and right if anybody ever blew one out.

But I’m curious; when you said the back end your truck was squirrley with the SRA‘s, how heavy were you pulling and what did you have the tires inflated to? I mean, at least I can understand partially why somebody would want an eight ply or 10 ply truck tire on their truck if they were pulling really heavy all the time but in all seriousness, if you inflate those SRA‘s to their max pressure, I just can’t see how sacrificing your ride quality is worth it on that heavy-built of tires but again, I guess that’s just me.

So far, I’ve yet to haul anything really heavy on my new Michelin‘s that are pretty much the same thing as the SRA’s but I guarantee you if I ever do, I will be inflating them to their maximum pressure and I betcha I’ll be just fine.

I believe from the Goodyear site. It has been over a year ago that I saw it.

I could be mistaken, because at that time I was looking all over for tires. I will try to find it again.

When I got my truck it had one RWL SR-A, and the rest were all blackwalls, so maybe they had been swapped put before I bought it? Can't remember the speed ratings of the originals, 113R, maybe?

Back down the rabbit hole......

 

[EdGs]

This is from Tirepressure.com
It is not what I saw before, still looking, but you can see how one could get confused really quick.

(at least, how I can.....lol)

 

[Jim113]

What P.S.I. do you run in your tires?

If you have OEM sized tires on your truck then check the decal on the inside of drivers door pillar ... That will give you the recommended tire pressure ... If using a different size tire then you should state the size and those with similar tires can offer a better idea of what PSI you should use ...

 

[corneileous]

If you have OEM sized tires on your truck then check the decal on the inside of drivers door pillar ... That will give you the recommended tire pressure ... If using a different size tire then you should state the size and those with similar tires can offer a better idea of what PSI you should use ...

Not always. The size don’t mean nothing when there’s many different load ranges in that size.


Sent from my iPhone using Tapatalk

 

[corneileous]

I believe from the Goodyear site. It has been over a year ago that I saw it.

I could be mistaken, because at that time I was looking all over for tires. I will try to find it again.

When I got my truck it had one RWL SR-A, and the rest were all blackwalls, so maybe they had been swapped put before I bought it? Can't remember the speed ratings of the originals, 113R, maybe?

Back down the rabbit hole......

This is from Tirepressure.com
It is not what I saw before, still looking, but you can see how one could get confused really quick.

(at least, how I can.....lol)

View attachment 239573

I don’t know man, don’t know what to tell you other than to do what I did was go to tirerack.com, enter all the credentials for our trucks and then do a side by side comparison for all three of the Goodyear SRA’s they have in the stock 20” size and you’ll see for yourself that they’re all three pretty much the same as far as maximum tire pressure and how much weight they will hold that pressure. That’s all I can say.


Sent from my iPhone using Tapatalk

 

[6.7CumminsDrvr]

I know I’ve already quoted this post once before but the only reason why I’m even bothering to quote it a second time is because I just got off the phone with my local discount tire and started talking to him about this and I quoted to him everything that you said in this post above and even he even said and even he’s never heard anything about a tire being magically derated from its capacity when it’s put on a certain vehicle so once again, this 1.1 stuff must mean something else totally different or apply to something else because even he himself said that when a manufacturer puts a tire on their vehicles brand new and they say that that tire must be inflated to that pressure, that only means that that’s all the pressure that that tire needs to have in it to support the weight that the truck can only handle. Hell, who knows, maybe that is what you, and and so many other people have been trying to say all along but just got a ****** way of explaining it.


Sent from my iPhone using Tapatalk

I’ll send you the link to the load inflation table I was referencing..........it’s from Toyo Tires which is a pretty well know tire manufacture.

I don’t know your local tire guy and my intent is not to stir up conflict but in all honestly, if your your local guy in the tire industry has no idea about the afore mention load inflation tables and where they come from, I’d find another tire guy.


https://www.toyotires.com/tires-101/tire-load-and-inflation-tables



https://www.toyotires.com/media/3729/application_of_load_inflation_tables_20200723.pdf


Just trying to pass along some knowledge, not here say or misinformation.

 

[corneileous]

I’ll send you the link to the load inflation table I was referencing..........it’s from Toyo Tires which is a pretty well know tire manufacture.

I don’t know your local tire guy and my intent is not to stir up conflict but in all honestly, if your your local guy in the tire industry has no idea about the afore mention load inflation tables and where they come from, I’d find another tire guy.


https://www.toyotires.com/tires-101/tire-load-and-inflation-tables



https://www.toyotires.com/media/3729/application_of_load_inflation_tables_20200723.pdf


Just trying to pass along some knowledge, not here say or misinformation.

So, tell me something.... why do you believe in this so much? What does this tell you that it’s obviously and apparently not telling me? Do you really believe that a tire- since it’s so talked about on here and since it’s so well known, let’s just use the GoodYear SRA P275/60/R20. Do you really believe that this tire won’t support what is says stamped on the sidewall if it’s all the sudden put on a truck? How?

And no, I’m not aiming to stir up conflict either but I am highly intrigued to how someone can believe into this. I mean what, since you haven’t really addressed anything I’ve said in response to you, are you trying to confuse this with actual load ratings on any given truck? Is that why you’re saying this tire in particular will only hold 2,365 pounds at 39 psi, nothing more, nothing less? What vehicle could I trust with the markings on the tire? Is there any vehicle that this tire will safely support 2,601 pounds at 44psi?

But you know, this wasn’t just a local mom and pop tire store, this was Discount Tire. You know, they look like this....

.....and they are practically everywhere.

There are about 7 or 8 of these stores in about a 150 mile radius of me so I guess tomorrow I can call each one of them but I’m almost one hundred percent certain I’ll get the same answer so if I do, are you gonna condemn each place? What about when I first stated talking to you and said that three well known tire brands told me the same thing “my local tire guy” told me? No comment towards that?

Look, I’m not trying to be an *******. I’m just trying to understand why you believe into this or if you’re actually sure what it actually means that you’re believing into.


Sent from my iPhone using Tapatalk

 

[Hogman338]

Yep you have to derate p series tires on trucks & suvs.

 

[6.7CumminsDrvr]

@Cornballnelius
So, tell me something.... why do you believe in this so much? What does this tell you that it’s obviously and apparently not telling me?

Answer to the first question is simple, its a U.S. federal vehicle safety regulation. These are issued by the NHTSA. The NHTSA falls under the U.S. Department of Transportation.

Second question, I don’t know sir. The material is written in plain English, so I have no idea why you think it’s telling me something different than what it tells you.

Do you really believe that this tire won’t support what is says stamped on the sidewall if it’s all the sudden put on a truck? How?

I do beleive the tire will support the weight stampted on the tire, never disputed that. I simply stated when that particular tire is used in a light truck application FMVSS REGULATIONS set forth by the NHTSA states their load carrying capacity is de-rated by a factor of 1.1 which in the case of the stock Goodyear’s equates to 2,365 lbs. I didn’t make this up, the U.S. D.O.T. did.

And no, I’m not aiming to stir up conflict either but I am highly intrigued to how someone can believe into this.

Again, I’m citing Federal guidelines so I fail to understand why you are so intrigued by the fact I believe this. What is it about federal regulation that you are so adverse to? Just because you and every tire guy you’ve spoken with in your area have never heard of these regulations doesn’t mean they don’t exist and are not pertinent.

I mean what, since you haven’t really addressed anything I’ve said in response to you, are you trying to confuse this with actual load ratings on any given truck? Is that why you’re saying this tire in particular will only hold 2,365 pounds at 39 psi, nothing more, nothing less? What vehicle could I trust with the markings on the tire? Is there any vehicle that this tire will safely support 2,601 pounds at 44psi?

I have directly addressed and responded to your question with written documentation. I am not confused about load ratings on any given truck (I am talking specifically about the tire load ratings). In regards to what vehicle you can trust with the markings on the tire, it depends on the vehicle and the tire. THATS WHY THE LOAD INFLATION TABLES EXISTS. To answer the last question in this section, any car, minivan, or less than full size SUV.

Not going to comment on the pic you sent other than thank you. My buddy Norman who happens to be the manager at a Discount Tire in my area will be relieved to know you’ve confirmed the Discount Tire stores up in your area look just like the ones here in Atlanta.


There are about 7 or 8 of these stores in about a 150 mile radius of me so I guess tomorrow I can call each one of them but I’m almost one hundred percent certain I’ll get the same answer so if I do, are you gonna condemn each place? What about when I first statedtalking to you and said that three well known tire brands told me the same thing “my local tire guy” told me? No comment towards that?

I didn’t tell you to condemn any of them, I suggested you find another tire guy (that may very well be someone else at the same store who’s a little more informed). To your statement about my “no comment on that”: I replied in my previous post citing the load inflation tables from Toyo Tires. They are a very well known national brand so I again question who you’re talking to or getting replies from. I seriously doubt Toyo is held to different regulations than the “three well known tire brands” you referenced above. Toyo is clearly aware of these regulations...........

Look, I’m not trying to be an *******. I’m just trying to understand why you believe into this or if you’re actually sure what it actually means that you’re believing into.

I’m not trying to be an azzhole either. My belief in these regulations is just the same as regulations set forth by the I.R.S. or the D.O.T. I am being very specific and citing federal regulations that are published. I am 100% sure I understand and comprehend what I’ve read.

Maybe some other fellow members will chime in here, this topic has been discussed more than a few times on this forum and more than a few members other than me have referenced the very same information.

 

[corneileous]

Yep you have to derate p series tires on trucks & suvs.

Why? Instead of just agreeing with this unconditionally and saying you have to, how about filling in the blanks? Other than the fact of my truck only being allowed to be weighted down so much due to its own limitations, tell me why my tires won’t hold what the numbers on the sidewalls say they can if aired to the specific pressure?


Sent from my iPhone using Tapatalk