Tire Pressures in TV

[specialK]

[QUOTE=Mopar_Earl;946760]Your coopers are the wrong load range if you have a 2500 or 3500 truck, max sidewall pressure would be 80. Load range E. Your tires are under rated if you have anything heavier than a 1500.






Not true. Many E load range tire are only 65 psi. It's why there's a plethora of F load range tires out now, to be capable of 80 psi. Ford and Chevy have been 65 psi for a while, Ram was the one that made that switch early on. And swapping tires was tough, as 35x12.50-20 E load range tires are 65 psi from most manufacturers. Until recently.

[specialK]

The tires are taken into account when the vehicle manuf assigns psi recommendations. That psi will do whatever the vehicle is capable of. There's no reason to change it, unless you notice irregular wear.

[Mopar_Earl]

[QUOTE=specialK;949029]

Originally Posted by Mopar_Earl

Your coopers are the wrong load range if you have a 2500 or 3500 truck, max sidewall pressure would be 80. Load range E. Your tires are under rated if you have anything heavier than a 1500.






Not true. Many E load range tire are only 65 psi. It's why there's a plethora of F load range tires out now, to be capable of 80 psi. Ford and Chevy have been 65 psi for a while, Ram was the one that made that switch early on. And swapping tires was tough, as 35x12.50-20 E load range tires are 65 psi from most manufacturers. Until recently.

That was the first I ever in my 43 years heard of a load range E max inflation of 65 lbs. If you read the rest of the thread you would see I acknowledge it. I'm still shocked such a tire exists.

Note, none of my Rams had 65 lb E tires. My 93, 07 nor my current 18. They are all 80 lbs max inflation.

F range should be 95 lbs max inflation.


Earl

[Evman]

Our 2wh drive 3500 came with D load tires and they were 65 Lbs air pressure. I changed them at 13K miles for the same tire but E rated. I also bought a new car and changed the tires at 200 miles. chevman

[jadatis]

Did you read E- load on tire, or maximum pressure 80 psi, and so assumed E-load.

In Europe Continental group tires give in case of D- load 65psi right behind the sises and sevice-descriptions, and further on tire " maximum inflation pressure of 10 psi higher so 75 psi.

On CP tyres( camping pneu, tipically european to unofficially cover overloading) even 80 psi then.

Mayby your brand also stepped over to that double pressure, so search further on tire sidewall.
Look for D-load/ LRD / 8PR and that double
pressure.

But some sise-systems give E- load 65 , D- load 50

See atached pictures

[citgodan]

No, mine stated load E rated, and 3750 lbs. Max

[jadatis]

Wrong first picture and could not correct, so here right one, with the 65 psi behind serv descr.

But what are the sises of your tire?

[citgodan]

My tire is a 325/60/R20

[jadatis]

Stange .
325/60R20 3750 lbs maxload is loadindex 126.

In Europe 255/55R18 E- load LI 120 at 83 psi.
Same in USA 115 LI at 80 psi.

You should expect even higher maxload for your tires. Mayby in this exeptional sise the E- load is AT 65 psi, yust the same as other sise-systems like section width given in inches.

[citgodan]

Originally Posted by jadatis

Stange .
325/60R20 3750 lbs maxload is loadindex 126.

In Europe 255/55R18 E- load LI 120 at 83 psi.
Same in USA 115 LI at 80 psi.

You should expect even higher maxload for your tires. Mayby in this exeptional sise the E- load is AT 65 psi, yust the same as other sise-systems like section width given in inches.

We are definitely talking different specs between the 2 continents

[Mopar_Earl]

Europe?? People are getting confused without throwing in overseas tire information!


Earl

[Evman]

Originally Posted by jadatis

Wrong first picture and could not correct, so here right one, with the 65 psi behind serv descr.

But what are the sises of your tire?

A C is showing for that tire so is it a C range tire?

[barryg]

The tire placard on the door jamb is not there for comfort or durability it is there by federal law and the psi given for the oem tires is so that the load rating is adequately covered for the oem gvw of the vehicle. You can find the rules they have to follow in the federal register

The tire size 325/60/20 is one of those load range e tires that is max 65 psi. That is due to the large volume of air they hold air is what holds the vehicle weight the tire just holds the air and since it is larger it does not require the same psi as a smaller volume tire
The load inflation table for a 325/60/20 is
Psi. Load lbs
35. 2535
40. 2680
45. 2915
50. 3195
55. 3350
60. 3560
65. 3750

So if you look at the max front and rear axle rating on your door placard divide those numbers by two and you will have your front and rear axle gvw per tire use that number in the above list to find your proper psi for your vehicle with the Cooper tires at max oem gvw. You could add 5psi if you like for a bigger safety margin

If you weigh your truck front axle and rear axle empty or your normal driving weight then you will have that information to set a lower psi for non towing/loaded conditions if you wanted

Do the same with your trailer hooked up and you will know what psi is required for when you are towing it and you may very well find it is not max pressure of the tire so you could enjoy a better ride and possibly better wear characteristics on the tire running that psi. Just like oem tires on the placard it does not say 80psi it says whatever it says for the oem tires and the oem designated max load rating