Tire pressure help

[Env1ous]

Originally Posted by geeman789
Originally Posted by Env1ous


Don't want a soft ride. But when I hit bumps my rear kicks out on me. So I was more so wondering if I had them over inflated and I do. So it does hit bumps a little stiffer than it should


ALL unloaded trucks do THAT ... ! Put 1000 lbs in the back ... that will fix it ! Or run the rear tires at even lower pressures ... when EMPTY.


I have had 4 trucks and probably put about 100k miles on them. It is the tires. I had E rated duratracs, BFG KO2s, and some P rated tires. The Ps were a better ride but did not last lol
Got way too many flats. These are the only tires that kick out on me like this. I think they are a lot more sensitive to PSI than all the other brands because I had the same PSI in the KO2s and the duratracs.

 

[Env1ous]

Originally Posted by Duffyjr
I wanted to stay with LT tires for my 89 k1500 because that's whats on the door jam and wanted the Cooper AT3's and they only came in E rated or at least that's all my tire shop could get. When I first drove it off the lot I though it was somewhat ruff so when I got home I checked and they had put 50 lbs in them. After a couple thousand miles I decided to drop them down to 45 lbs and what a difference it made so I keep them there, much better on the back. I tried 40 lbs but that made it handle somewhat bad, like the steering was delayed.


Thank you! Yes gonna run them at 45psi and see how she feels! I noticed the Cooper's are more sensitive to PSI than the other brands I have tried.

 

[Dave1027]

What does the door placard say? Usually it says somewhere in the 32 lb range unless carrying a load. You want the tires to provide a certain amount of cushion. Also, if aired up too much the middle section will wear prematurely.

 

[dave1251]

Originally Posted by das_peikko
What does it say on the tire for the maximum? I always go 4 PSI below the maximum on the tire.


That is pretty dumb advice.

 

[Env1ous]

Originally Posted by dave1251
Originally Posted by das_peikko
What does it say on the tire for the maximum? I always go 4 PSI below the maximum on the tire.


That is pretty dumb advice.


Solid advice when you have OEM tires. But once you have different load ratings and sizes a lot changes.

EDIT: My eyes skipped a few lines. I thought I was replying to the one saying use the placard in the door jamb. lol.

DO NOT follow this advice

 

[OVERKILL]

Originally Posted by Env1ous
Originally Posted by dave1251
Originally Posted by das_peikko
What does it say on the tire for the maximum? I always go 4 PSI below the maximum on the tire.


That is pretty dumb advice.


Solid advice when you have OEM tires. But once you have different load ratings and sizes a lot changes.


Going by some "rule of thumb" based on the sidewall pressure is never "solid advice", which is what das_peikko was advocating. You want to go by the placard if you have OEM sized tires, not the sidewall. In your case, since you have deviated tire type and size, going by the load tables is about the best one can do, and then fine tune from there, which you are doing.

 

[Env1ous]

Originally Posted by OVERKILL
Originally Posted by Env1ous
Originally Posted by dave1251
Originally Posted by das_peikko
What does it say on the tire for the maximum? I always go 4 PSI below the maximum on the tire.


That is pretty dumb advice.


Solid advice when you have OEM tires. But once you have different load ratings and sizes a lot changes.


Going by some "rule of thumb" based on the sidewall pressure is never "solid advice", which is what das_peikko was advocating. You want to go by the placard if you have OEM sized tires, not the sidewall. In your case, since you have deviated tire type and size, going by the load tables is about the best one can do, and then fine tune from there, which you are doing.


No my eyes skipped a few lines. I thought I was reply to the comment of following the placard inside the door jamb LOL
You are right on this one. This is bad advice.

 

[OVERKILL]

No worries

 

[das_peikko]

Originally Posted by Quattro Pete
Because that's what he was told by a "reliable source"

https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/5057191/tire-pressure

Just ignore him. He's trolling as usual.

I call him a reliable source because he's been my best friend since the military days. He's had his own automotive machinist business for well over 20 years. He's the master at drilling out broken bolts. Whatever he says about cars is usually always true. I'd be happy to PM you his phone number is you'd like Pete. Ever since I raised my air pressure to 40 PSI (per his suggestion) the car handles a lot tighter.

 

[Quattro Pete]

Originally Posted by das_peikko
I'd be happy to PM you his phone number is you'd like Pete.

No thanks. I'd take the recommendation of my car manufacturer over your friend's questionable advice. Handling in all my cars is already tight without having to run excessive tire pressure.

If the OP was to follow your friend's advice, he'd end up with 76 PSI in his tires.

 

[zeng]

Originally Posted by Quattro Pete
Originally Posted by RamFan
Originally Posted by das_peikko
I always go 4 PSI below the maximum on the tire.


Why?

Because that's what he was told by a "reliable source"

https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/5057191/tire-pressure

Just ignore him. He's trolling as usual.

I'm with Das as I see no issue other than harsh ride.
OMG, talking about ride being harsh on an E tire ?

 

[Quattro Pete]

Originally Posted by zeng
I'm with Das as I see no issue other than harsh ride.
So you are also suggesting 76 PSI for OP's tires?

 

[zeng]

Originally Posted by Quattro Pete
Originally Posted by zeng
I'm with Das as I see no issue other than harsh ride.
So you are also suggesting 76 PSI for OP's tires?

Yes, 76 psi for this E tires.
There is no problem as far as the tires are concerned.
But does OP requires/needs it ? No.
If OP so desires, why not?
That's a question for OP, as an owner, to decide IMHO.

 

[Kjmack]

Originally Posted by Quattro Pete
Originally Posted by zeng
I'm with Das as I see no issue other than harsh ride.
So you are also suggesting 76 PSI for OP's tires?

Tires work in harmony with the suspension , over the top inflation like some are suggesting, is going to affect the suspension parts drastically reducing their lifespan.

 

[Quattro Pete]

Originally Posted by zeng
If OP so desires, why not?
That's a question for OP, as an owner, to decide IMHO.

He's running 48 PSI right now and already finding it too stiff, so you figure it out from there if 76 PSI is the right way to go for him.

 

[OVERKILL]

Originally Posted by zeng
Originally Posted by Quattro Pete
Originally Posted by zeng
I'm with Das as I see no issue other than harsh ride.
So you are also suggesting 76 PSI for OP's tires?

Yes, 76 psi for this E tires.
There is no problem as far as the tires are concerned.
But does OP requires/needs it ? No.
If OP so desires, why not?
That's a question for OP, as an owner, to decide IMHO.


He literally created the thread because he didn't like how the tires rode at 48psi. What do you think his perception would be of them at 76? Good grief

It's not a matter of it being a "problem", this is a load-range E tire on a 1/2 ton pickup that originally spec'd P-metric tires and isn't rated to carry anywhere NEAR the weight required for a load range E tire inflated to a pressure necessary to take advantage of that rating. Hence my posting of the load table documentation that will properly guide him toward a reasonable pressure choice that satisfies the load carrying requirements for tires fitted to his vehicle. At this juncture, he's determined that this is 45psi and which should result in the more compliant ride that he's seeking.

 

[zeng]

Originally Posted by OVERKILL
Originally Posted by zeng
Originally Posted by Quattro Pete
Originally Posted by zeng
I'm with Das as I see no issue other than harsh ride.
So you are also suggesting 76 PSI for OP's tires?

Yes, 76 psi for this E tires.
There is no problem as far as the tires are concerned.
But does OP requires/needs it ? No.
If OP so desires, why not?
That's a question for OP, as an owner, to decide IMHO.


He literally created the thread because he didn't like how the tires rode at 48psi. What do you think his perception would be of them at 76? Good grief

It's not a matter of it being a "problem", this is a load-range E tire on a 1/2 ton pickup that originally spec'd P-metric tires and isn't rated to carry anywhere NEAR the weight required for a load range E tire inflated to a pressure necessary to take advantage of that rating. Hence my posting of the load table documentation that will properly guide him toward a reasonable pressure choice that satisfies the load carrying requirements for tires fitted to his vehicle. At this juncture, he's determined that this is 45psi and which should result in the more compliant ride that he's seeking.

Not trying to be argumentative, I repeat:
Originally Posted by zeng
I'm with Das as I see no issue other than harsh ride.


Quote
But does OP requires/needs it ? No.
If OP so desires, why not?
That's a question for OP, as an owner, to decide. IMHO.


The fact remains:
an E range tire is designed for Das' position of :
Quote
I always go 4 PSI below the maximum on the tire.

...... which I backed , as far as a said tire is concerned.
I've no qualms OP not selecting 76 psi in this application, rightly.

Originally Posted by Env1ous


80PSI max. LOL Not going to 76. Don't need it that high. I just saw the max on it.



Edit:add OP's quote.

 

[OVERKILL]

Originally Posted by zeng

The fact remains:
an E range tire is designed for Das' position of :
Quote
I always go 4 PSI below the maximum on the tire.

...... which I backed , as far as a said tire is concerned.
I've no qualms OP not selecting 76 psi in this application, rightly.


An E-range tire is designed to operate with pressure up to the maximum indicated, depending on the load rating required. As I already noted, he's got a 1/2 ton truck, his application is entirely incapable of utilizing the additional load capacity of the "E" rating. Ergo, what the tire's MAXIMUM weight capacity per design is, is entirely irrelevant to his application. This is well supported by how these tires are used in application. My old F-250 spec'd 80psi loaded in the rear and 55psi in the fronts, which were the SAME TIRES. Because the payload capacity wasn't required on the front axle. Going by "Das's position" here, I'd have been running 76psi in all 4 wheels, which ran completely contrary to what Ford indicated.

OP's quote from the opening post:
Originally Posted by Env1ous
I have mine aired up to around 48 PSI. Is that too much for daily driving? Ride does seem a little stiff and it takes bumps hard.


Per the load tables, he only requires 45psi in those tires to match the load carrying capacity of the OEM fitted ones.

 

[Env1ous]

Originally Posted by OVERKILL
Originally Posted by zeng
Originally Posted by Quattro Pete
Originally Posted by zeng
I'm with Das as I see no issue other than harsh ride.
So you are also suggesting 76 PSI for OP's tires?

Yes, 76 psi for this E tires.
There is no problem as far as the tires are concerned.
But does OP requires/needs it ? No.
If OP so desires, why not?
That's a question for OP, as an owner, to decide IMHO.


He literally created the thread because he didn't like how the tires rode at 48psi. What do you think his perception would be of them at 76? Good grief

It's not a matter of it being a "problem", this is a load-range E tire on a 1/2 ton pickup that originally spec'd P-metric tires and isn't rated to carry anywhere NEAR the weight required for a load range E tire inflated to a pressure necessary to take advantage of that rating. Hence my posting of the load table documentation that will properly guide him toward a reasonable pressure choice that satisfies the load carrying requirements for tires fitted to his vehicle. At this juncture, he's determined that this is 45psi and which should result in the more compliant ride that he's seeking.


This is the run around I got on other forums while asking. I liked the chart and info you provided. I knew there had to be a science behind it that made more sense.

 

[OVERKILL]