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Probably a dumb (tire) question, but y'all should be used to that....

T

TruckinThumper

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Tire pressure.
Stock 2500 Tradesman
6.4L
8' box
4x4

OEM Firestones.
door pressure states max 60 front and 65 rear.
Seems the dealer and others, want to say bump it up to in the mid to high 70s while towing.
I am having a hard time coming to grips with that. Pretty sure if that were true, Ram would have made that on the door sticker too, or even in the manual.
Pretty sure Firestone would make that well known.
Having owned and driven 18 wheelers enough, I have NEVER seen that ideology.
We would run a few pounds less on steering but never changed do to the load.

So the dumb question is, am I am idiot?
 
Everything I’ve been told is the tire pressure on the door tag is what the tires need to be at for max vehicle capacity. I always run lower pressure unless I’m towing or hauling, then I run the 60/65 psi.
 
Although I don't disagree with the other comments, it could be that some folks that recommend more pressure have reason to believe that you will experience better tire wear when towing at higher pressure or maybe it stabilizes the towing experience a bit more

Either way, a little more pressure won't hurt much other than possibly ride quality slightly. As long as your inflation pressure is within the max listed on the tire, it really can't hurt much. I've never paid much attention to tire pressure ratings as listed on the truck but typically defaulted to the max tire pressure on the tire when towing or hauling very much and had good results. It's a little much on the rear of a dually though and will cause the centers of the tread to wear out before the edges but you're not talking dually.
 
As stated pressure on the door sticker is for the stock tire size/load rating for achieving the axle weight ratings.

Firestone does make it well known that you can run more pressure since it’s printed on the sidewall to have a max load of 3640lbs @ 80 psi.

For loads other than max, or max axle rating, there are publish load and inflation tables. I prefer the Toyo one because it seems to be the most comprehensive. You don’t have to use one from your tire manufacturer since they are standardized for a given size and load rating.

If you know your axle weights feel free to air down, otherwise I’d run door pressure. There are many advantages to knowing your weights and running proper pressure. You get better traction (accel, decel, and lateral), better tire life, better ride, and you’re less susceptible to road hazards vs running max door pressure or max sidewall pressure regardless of the load.

My empty pressures are usually 55/35, and loaded depends on what I’m doing.

 
I'm going to assume (yeah, I know what happens when you assume) whomever you spoke with (dealer and others) just don't understand that there are different PSI ratings across the lineup. Most of the door stickers I've seen for those with 18" and 20" wheels state 80PSI in the rear, versus the 60PSI that yours shows (assuming 17" wheels). Ignore the ignorance and you'll be good to go.
 
LateToTheParty said:
I'm going to assume (yeah, I know what happens when you assume) whomever you spoke with (dealer and others) just don't understand that there are different PSI ratings across the lineup. Most of the door stickers I've seen for those with 18" and 20" wheels state 80PSI in the rear, versus the 60PSI that yours shows
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That has changed in recent years. My 18 2500 CTD showed 80psi for the rears on the factory sticker, as did all my other 3/4tons over the years. My 22 2500 CTD shows 60psi. Same basic truck.
 
LateToTheParty said:
I'm going to assume (yeah, I know what happens when you assume) whomever you spoke with (dealer and others) just don't understand that there are different PSI ratings across the lineup. Most of the door stickers I've seen for those with 18" and 20" wheels state 80PSI in the rear, versus the 60PSI that yours shows (assuming 17" wheels). Ignore the ignorance and you'll be good to go.
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Just how the 18’s and 20’s are labeled for a 6K RAWR. It’s all that’s needed. The 3500 SRW shows 80 psi for the 7K RAWR.

17’s would actually require more pressure for the same load, and are not capable of a 7K RAWR.
 
Cseybert said:
It’s always good to run at max pressure if loaded or at highway speeds. Both increase heat and a low tire will fail.
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Hardly, lol.

It’s always best to run the proper pressure. That’s not always max pressure. Tire companies are aware of this, and why there is literature and tables for running pressure other than max.

It is better to be overinflated than underinflated, and max pressure for the tire/axle is best when you don’t know your weights.
 
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On my PW, with the tires set at max pressure, I could see daylight under the outer treads of the tire. So that's not a good thing.
Even at the minimum TPMS threshold alarm of 50 PSI, I could still see daylight under the outer treads of the tires, more so in the rear. So still over inflated for a empty truck.
Weighed my truck at the scales.
Front: 4280
Rear: 3080
Total: 7360
 
AH64ID said:
Hardly, lol.

It’s always best to run the proper pressure. That’s not always max pressure. Tire companies are aware of this, and why there is literature and tables for running pressure other than max.
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Well, I don’t know if you’re old enough to remember the firestone tire issues on Ford explorers years ago. The cause of failures mainly running overloaded vehicles with low tire pressure. But Ford and firestone paid out millions of dollars because of jury awards.
 
Cseybert said:
Well, I don’t know if you’re old enough to remember the firestone tire issues on Ford explorers years ago. The cause of failures mainly running overloaded vehicles with low tire pressure. But Ford and firestone paid out millions of dollars because of jury awards.
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Ummm… quite the opposite. On our 98 explorer they lowered the tire pressure due to the rollovers.

I may be a couple psi off, but recall them dropping to 26 from 35. Rollover tests that failed at 35/35 passed at 26/26.

It all comes back to proper pressure. Underinflated is much worse than overinflated, but proper is best. Proper does not equal max.
 
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AH64ID said:
Ummm… quite the opposite. On our 98 explorer they lowered the tire pressure due to the rollovers.

I may be a couple psi off, but recall them dropping to 26 from 35. Rollover tests that failed at 35/35 passes at 26/26.

It all comes back to proper pressure. Underinflated is much worse than overinflated, but proper is best. Proper does not equal max.
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Fully loaded and at highway speeds I believe it comes into play.JMO
 
Cseybert said:
Also had a explorer from 1997 to 1999
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So they would have dropped the tire pressure to reduce the chance of a rollover, just like on our '98 Explorer.

Our Explorer used a P235/75R15 tire. 35 psi is rated for 2028lbs/tire and 26 psi is rated for 1753lbs per tire. 1753x4 is 7,012, more than adequate for the ~5,500 GVWR on the Explorer. Even at max 8.8" RAWR of 3,200 lbs the 26 psi is adequate, and makes sense why they dropped the pressure.

IMHO the explorer issues were suspension related, not tire related, but the tires took the rap.
 
Oh, actually, Ford had them at 26 psi’s and fire stone said they should be at at least 30 psi if you go back and read through the documentation from the lawsuits
 
Cseybert said:
Oh, actually, Ford had them at 26 psi’s and fire stone said they should be at at least 30 psi if you go back and read through the documentation from the lawsuits
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Maybe we sold our before then because the only thing I recall was a drop down to 26 psi due to rollovers. It was sold in late 99 or early 2000.

I also found a bunch of ford test results showing the same thing, 35 down to 26 but that was also before out 98.

But it's all really a mute point, as this really doesn't have anything to do with these trucks (or any vehicle) and proper inflation of good tires based on weight and published tire pressure charts.

Underinflated is a bad idea, overinflated has some drawbacks, and proper pressure just works the best.

If tire manufacturers didn't want you running proper pressure for the load they wouldn't go thru the time and effort of publishing load and inflation tables.

The recommended pressure on the front of all SRW Ram's, and the rear of 19+ truck being below max pressure points to the validity of proper pressure for the load.
 
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