2023 2500 Tradesman Tire Pressure

[Ratman6161]

Like I said above my pillar is front 60 rear 65 for the stock 275 70 18 Firestone Transforce ATs. The manufactures inflation chart from Firestone for the OEM tires shows https://www.google.com/url?sa=t&sou...cs-sites/firestone/TBR/load-inflation-tabmuch lower tire pressure of just over 45 psi at 2500 pounds per tire than the door post shows me.

http://les/mar2015/FS_TBR_load-infl...kQFnoECC0QAQ&usg=AOvVaw1yGrPnBuAVJzhV4iktwW6z

I would truly love to hear how Ram comes up the the pillar inflation pressures and what their rational is for recommending tires be so over inflated. Got to be a reason but I sure can't figure out what it is.

I can hazard a guess how they come up with it. In the chart you linked to, if you find your tire size and look in the column for 65 psi, it says the load carrying capacity of the tire at that pressure is 3195. 3195 X two tires = 6390. Guess what the Gross Rear Axle Weight Rating on a gas engine Ram 2500 is. Hint...its 6390. So I don't think its a coincidence that they tell you to use a pressure that ensures your tires are able to carry the same load as the axle. But to me that means that it really is not necessary to use 65 psi when the truck is unloaded. Just my opinion.

What I'm now curios about is why mine has a sticker that says to use 70 instead of 65. I suspect that its because I have the 20 inch wheels with size 285/60-20 but unfortunately I'm not finding that size in the chart.

Edit: I found another source for my size. Its not an official firestone reference but it looks useful.

LT285/60R20 Tire Pressure Chart - TirePressure.com

Find corresponding tire load capacity at specified tire inflation pressures for LT285/60R20 tires to maintain proper tire inflation for a safe drive.

tirepressure.com

For my size i.e. 285/60-20 it is different. At 65 PSI it only has a load carrying capacity of 3085. So to get at least as high as the truck's axle rating of 6390, I have to go to 70 psi which gets me a load carrying capacity of 3285 x 2 = 6570. Of course even with my travel trailer hooked up, I'm nowhere close to the GRAWR but even so, when towing, Ill go with at least the 70 psi

 

[Dean2]

I can hazard a guess how they come up with it. In the chart you linked to, if you find your tire size and look in the column for 65 psi, it says the load carrying capacity of the tire at that pressure is 3195. 3195 X two tires = 6390. Guess what the Gross Rear Axle Weight Rating on a gas engine Ram 2500 is. Hint...its 6390. So I don't think its a coincidence that they tell you to use a pressure that ensures your tires are able to carry the same load as the axle. But to me that means that it really is not necessary to use 65 psi when the truck is unloaded. Just my opinion.

What I'm now curios about is why mine has a sticker that says to use 70 instead of 65. I suspect that its because I have the 20 inch wheels with size 285/60-20 but unfortunately I'm not finding that size in the chart.

Edit: I found another source for my size. Its not an official firestone reference but it looks useful.

LT285/60R20 Tire Pressure Chart - TirePressure.com

Find corresponding tire load capacity at specified tire inflation pressures for LT285/60R20 tires to maintain proper tire inflation for a safe drive.

tirepressure.com

For my size i.e. 285/60-20 it is different. At 65 PSI it only has a load carrying capacity of 3085. So to get at least as high as the truck's axle rating of 6390, I have to go to 70 psi which gets me a load carrying capacity of 3285 x 2 = 6570. Of course even with my travel trailer hooked up, I'm nowhere close to the GRAWR but even so, when towing, Ill go with at least the 70 psi

Well that actually makes a great deal of sense to me, in terms of at least a rational explanation of how they came up with the numbers. Good job working that out.

Like you say though, that is still way over inflated for what an empty pickup weighs. Also like you, I air up to at least 65 all round if I am hauling or heavily loaded in the box. There the extra pressure does make a positive contribution.

 

[Riccochet]

Pressures on the door sticker are for max load. Meaning you are at or near your payload capacity. If your unloaded there's zero reason to run those pressures. Flippin miserable running tires that high.

I also find it odd that your door sticker shows pressures that high. That's nuts for a 2500. Mine show 60 front 65 rear, which if you look at the pressure chart for your tires will show the load they can carry at a given pressure. I just can't wrap my head around why it would want 80 psi in the rear. Could see that if it was a 3500. But a 2500 has a 10,000 GVWR. Don't need to come close to 80 PSI on your tires to exceed 10,000 lbs of load capacity.

 

[Tulecreeper]

Pressures on the door sticker are for max load. Meaning you are at or near your payload capacity. If your unloaded there's zero reason to run those pressures. Flippin miserable running tires that high.

I also find it odd that your door sticker shows pressures that high. That's nuts for a 2500. Mine show 60 front 65 rear, which if you look at the pressure chart for your tires will show the load they can carry at a given pressure. I just can't wrap my head around why it would want 80 psi in the rear. Could see that if it was a 3500. But a 2500 has a 10,000 GVWR. Don't need to come close to 80 PSI on your tires to exceed 10,000 lbs of load capacity.

I completely agree. What I can't understand is why, at that pressure, I'm not getting a hell of a bumpy ride.

 

[tron67j]

Tires are designed to do 2 things, carry weight and maximize handling. Strictly staying on road usage and tires spec'd to OEM or similar, adjusting tires to a pressure other than what is listed on the door jamb will impact handling characteristics. Is that always bad, can't say but the truck certainly will not react how it was designed to in all situations. Kind of think that's why door jambs don't provide 2 sets of values; loaded and unloaded.

 

[06 Dodge]

In my 2006 2500 with a CTD when not towing I ran 60 PSI rear and 65 PSI front, extra in front due too the diesel engine, I recall the door sticker had cold inflation 50 PSI & 70 PSI for max weight with OEM 265/70/17 E tires, I see no reason to run 75 PSI if not towing, BTW I ran my tires at that 60/65 PSI for 15 years and never once had a tire that failed...