Why Tire Pressure at Max 80psi recommended for 2500?

dexter · Jul 31, 2016

The door sticker on my 2500 6.4L says
Front 60 psi
Rear 80 psi

For the Firestone LT275/70R18 E that came with the truck it says the max psi is 80.

I'm wondering why the recommendation is for the max psi? I would think they would give a recommendation for something less than the max for empty and then allow the owner to air up when loaded or towing.

Also, if anyone know, I was thinking that if I was towing I would raise the front to 70 psi to handle the added weight. Should I just leave the front tires at 60 for the extra weight of towing?
Firestone Transforce HT

drittal · Jul 31, 2016

I don't know what year you have, I can't see sigs. Depending on year, going under 70ish psi in the rear will trigger the TPMS and give you a warning light. There used to be a way to lower the limit, but I'm not sure if it's still viable.

Those numbers are what the tires need to be inflated at to safely handle the max rated GVW. The TPMS is there and will go off if under the treshold because people air down the tires when empty for decent ride then forget to air up when when loaded up creating unsafe conditions.

You can run 80psi in the front if you want, it will only effect ride and tire wear.

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dexter · Jul 31, 2016

Thanks, that is very helpful info.
- it is a 2016

I've been running the rear in the 70s.

drittal said:
I don't know what year you have, I can't see sigs. Depending on year, going under 70ish psi in the rear will trigger the TPMS and give you a warning light. There used to be a way to lower the limit, but I'm not sure if it's still viable.

Those numbers are what the tires need to be inflated at to safely handle the max rated GVW. The TPMS is there and will go off if under the treshold because people air down the tires when empty for decent ride then forget to air up when when loaded up creating unsafe conditions.

You can run 80psi in the front if you want, it will only effect ride and tire wear.

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drittal · Jul 31, 2016

I think if you do some research here there are more threads on this. I run around 50psi rear empty. IIRC, someone posted a fact sheet about the Firestone tires we have that show its safe to run down around 45psi EMPTY. The tires should wear better at 50 psi empty compared to 80 psi empty.

The only problem is the tire pressure warning light and info screen that comes on when you start the truck. You can navigate away from the info screen, but then warning light won't go away unless you air back up to 80psi. That is unless the dealership can change the minimum threshold, which I don't think they can do on a 2016.

Good luck and be safe.

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spoon059 · Jul 31, 2016

drittal said:
Those numbers are what the tires need to be inflated at to safely handle the max rated GVW.

Not even remotely close to true. If I recall, the TransForce AT's are rated to over 3400 lbs per tire, or 6800 lbs per axle at full 80 psi. In a 2500 truck, you will NEVER be able to load that much weight on the rear axle without going over your 10K GVWR. Ram was simply too lazy to figure out the correct load rating for those tires to achieve the maximum capable load rating for the 3/4 ton truck. In reality, those tires are overinflated... grossly overinflated with no load in the back. Overinflation leads to excessive tire wear and improper contact patch on the roadway. Its pathetic that Ram won't acknowledge their mistake and took away the ability of the dealer to lower that threshold.

OP, I believe that you can be under the threshold by 20% before the TPMS triggers an alert. That means you can be at 64psi in the rears before it triggers. Unfortunately, once you trigger it you have to air back up to 80psi to reset it.

I've found that the truck rides very well and has an appropriate contact patch in the neighborhood of 55psi.

07MegaCabRam · Jul 31, 2016

They were able to do the adjustments up to the WiTech 2 update.

Tire manufactures were getting sued by people running lower pressure when failures had resulted.

WiTech2 update removed the ability to adjust. Thankfully, I was able to get my truck upgrade from my buddy who is a tech before this update.

My new tires say max 65 psi. So I had mine adjusted accordingly.

It's when you actually tow and have a good load behind you (which these trucks were designed for) - only then will you appreciate what the truck does and how it handles.

But yeah, for city driving and not towing, everyone wants to drop the pressure way down to soften the ride.

dexter · Jul 31, 2016

spoon059 said:
OP, I believe that you can be under the threshold by 20% before the TPMS triggers an alert. That means you can be at 64psi in the rears before it triggers. Unfortunately, once you trigger it you have to air back up to 80psi to reset it.

That's good to know, makes sense and in line with my gut feel.

I had 31x10.50R15/C on my dakota - recommended 35psi, max 45psi. I would only go near the max psi when towing.

drittal · Jul 31, 2016

Or tires are at the bottom. Ignore the highlight.

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Colt45automag · Aug 25, 2019

I purchased the bypass harness from Deerguy for my 2018 and thank God. My curb weight is 7500 and the truck is rated to 10000 so I can legally carry 1.25 tons. So, according to the Firestone 50-55psi all the way around is correct. FCA should be accountable and should make the TPMS adjustable without any wires modules or computers free of charge. I believe they should reimburse me for the wire, effort and software.

dhay13 · Aug 25, 2019

I see this is an old thread but will add my .02. When I bought my truck all 4 were at 80. The truck wandered badly. I lowered the fronts to about 70 and it rides like a different truck. Rears are at about 78 or so.
My son also has a 2018 2500 6.4 and towed his 8000lb camper 1500 miles a week after he bought the truck with ambient temps around 90. His rears hit about 85 with the heat buildup so he lowered them to just under 80. So just a heads up if you are towing heavy in higher ambient temps might want to put start the rears at about 75 or so cold

MADDOG · Aug 25, 2019

Just say "No" to 80PSI POS tires that Ram supplies with the HDs.

Rwgarrison23 · Aug 25, 2019

I run 60 psi all around unloaded. I may try 50/55.

Txkenpo · Aug 25, 2019

Yeah after driving my truck home from the purchasing dealership I noticed it rode very rough. Had 4x4 trucks all my life but it was like I had concrete tires. I looked at the pressure and front was at 90 and rear was at 94psi. I let a ton of air out all 4 at 60-62 psi now truck rides/ handles a lot better.

drittal · Aug 25, 2019

If you’re not loaded to max weight ratings, no need to drive around with your PSI maxed out.

Even then I think the fronts should only be aired to 65psi according to the door sticker.

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spoon059 · Aug 26, 2019

dhay13 said:
So just a heads up if you are towing heavy in higher ambient temps might want to put start the rears at about 75 or so cold

The tire pressure rating is the cold rating. It is perfectly normal for an 80psi tire to climb to 90 or higher. That's not a defect or something to cause concern. That's how they are designed. When I tow, it's 80psi cold. You actually create more heat if the tire isn't properly inflated...

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Why Tire Pressure at Max 80psi recommended for 2500?

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