What r u guys running psi?

[Crusty old shellback]

They also seem to vary a lot while running down the road. By "a lot" I mean up to three psi on a tire. Sunshine and pavement temps probably account for some of this.

Tires gain heat when running down the road so the PSI will rise. I see a 5 PSI rise after a freeway run.
On our off road race truck with 40" tires, I've seen up to 15 PSI difference after 150 miles of racing.

 

[Cpsram21]

Being 12 ply doesn’t mean they need less air for the load.

The ply rating (remember they don’t actually have 12 plys) doesn’t effect low load pressures. In your example with 35x12.50-18 a D, E, and F rated tire all can hold the same weight at 50 psi, 2910 lbs. The main difference in all 3 is the max pressure, which limits their max weight.

The D rated tire is limited to 50 psi.

The E and F rated tire can both hold the same weight at 65 psi, 3415lbs.

The E rated tire is limited to 65 psi.

The F rated tire can go to 80 psi and hold 3970 lbs.

All E rated tires i have ever purchased of any brand were 80 psi max so not sure what brand you are referring to that are limited to 65 psi. And when i looked at the weight chart on toyo's site originally before purchasing the f rated tires showed higher weight carrying capacity at 50 psi then e rated 10 ply tires so that's where i got my info from the manufacturer .

 

[H3LZSN1P3R]

Being 12 ply doesn’t mean they need less air for the load.

The ply rating (remember they don’t actually have 12 plys) doesn’t effect low load pressures. In your example with 35x12.50-18 a D, E, and F rated tire all can hold the same weight at 50 psi, 2910 lbs. The main difference in all 3 is the max pressure, which limits their max weight.

The D rated tire is limited to 50 psi.

The E and F rated tire can both hold the same weight at 65 psi, 3415lbs.

The E rated tire is limited to 65 psi.

The F rated tire can go to 80 psi and hold 3970 lbs.

The standard max pressures are usually:
P is 44psi max
C is 50psi max
D is 65psi max
E is 80psi max
F is 95psi max
G is 110psi max

 

[AH64ID]

Hit the scales again Friday. Had the whole family in the cab, 5 people, the dogs and some gear in the bed for a weekend away (that failed, but that’s another story)

5760/4340. Running 57/40 for pressure and it handles great.

Sadly I’d be over GVWR on a 2500. I wasn’t even heavy enough to get into Alt trailer height.

Something has to change on vehicle classifications, this is ridiculous. Luckily GVWR doesn’t mean crap in many states, including Idaho.

The standard max pressures are usually:
P is 44psi max
C is 50psi max
D is 65psi max
E is 80psi max
F is 95psi max
G is 110psi max

For standard sizes yes, but as you can see by the chart I posted not all flotation sizes follow that.

P is also a funny thing, some are 35 and some are 44. XL are 44, but not all load and inflation tables account for that. The toyo table for P tires doesn’t even go to 44 psi, despite them offering tires rated for it.

P are also only rated for 90% of their weight rating on SUV’s and pickups, but nobody ever talks about that.

All E rated tires i have ever purchased of any brand were 80 psi max so not sure what brand you are referring to that are limited to 65 psi. And when i looked at the weight chart on toyo's site originally before purchasing the f rated tires showed higher weight carrying capacity at 50 psi then e rated 10 ply tires so that's where i got my info from the manufacturer .

You should probably look again… there is only one line on the Toyo chart for you size tire and it covers D,E,F rated tires. This chart has been relatively unchanged for 10+ years, so I’m not sure what Toyo chart you looked at.

I have seen a lot of OEM load and inflation tables, and none of them work they way you described for LT tires of the same size with different load ratings.

StackPath

Lots of floatation tires are 65 psi max for E range tires. The same chart also shows this.

 

[Cpsram21]

Hit the scales again Friday. Had the whole family in the cab, 5 people, the dogs and some gear in the bed for a weekend away (that failed, but that’s another story)

5760/4340. Running 57/40 for pressure and it handles great.

Sadly I’d be over GVWR on a 2500. I wasn’t even heavy enough to get into Alt trailer height.

Something has to change on vehicle classifications, this is ridiculous. Luckily GVWR doesn’t mean crap in many states, including Idaho.



For standard sizes yes, but as you can see by the chart I posted not all flotation sizes follow that.

P is also a funny thing, some are 35 and some are 44. XL are 44, but not all load and inflation tables account for that. The toyo table for P tires doesn’t even go to 44 psi, despite them offering tires rated for it.

P are also only rated for 90% of their weight rating on SUV’s and pickups, but nobody ever talks about that.



You should probably look again… there is only one line on the Toyo chart for you size tire and it covers D,E,F rated tires. This chart has been relatively unchanged for 10+ years, so I’m not sure what Toyo chart you looked at.

I have seen a lot of OEM load and inflation tables, and none of them work they way you described for LT tires of the same size with different load ratings.

StackPath

Lots of floatation tires are 65 psi max for E range tires. The same chart also shows this.

View attachment 55240

I was probably looking at d and f rated instead of e and f but honestly it doesnt matter to me if i was off or not . I was mainly just trying to just give my psi for tire size that i run not get in a argument of who is right on a weight chart .

 

[AH64ID]

I was probably looking at d and f rated instead of e and f but honestly it doesnt matter to me if i was off or not . I was mainly just trying to just give my psi for tire size that i run not get in a argument of who is right on a weight chart .

It really doesn’t matter what load range you’re looking at, the ply rating doesn’t have any effect on what pressure you run for the weight it only effects the max pressure, which dictates the max load. At 50 psi they both carry the same weight.

Not trying to get into an argument, just pointing how how tire ratings work and how that pertains to the proper pressure for the load.