Rant on Factory TPMS Threshold settings

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gpatz

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OK guys, this is my point of view. I want to get the best performance and longest life from my tires and want to be safely within the tolerances of those tires.

I weighted my 2021 2500 Ram Laramie:

Factory Tires: Firestone Transforce AT LT275/70R18E max load per tire 3540 at 60 max psi
Full weight of truck + us + Full tank of diesel + hitch: total weight 8640
Front axle weight + us: total weight 5100
Rear axle weight + us + Full tank of diesel + hitch: total weight 3520

After calculating for proper tire pressure per above this what I got below:

Truck (8640) + connected Trailer (just past where the kingpin is connected to trailer) on the scale: 10620 lbs
total weight from above – Truck (8640) = Kingpin weight: (1980lbs)(2080lbs)2180lbs Max
Rear axle weight (3520) + Kingpin weight = Total load on Rear axle: 5700lbs
Truck Max GAWR (Max weight allowable RR axle is 6040lbs)
Front tires S/B set to: 45psi
Rear tires S/B set to: 50psi

Calculations of above weights being applied to the factory tires are below Mopars Placard recommendation.

After a 600 mile camping trip I measured the tread depth wear of Tires ( grant you that this may not be a long enough trip to judge that I am getting full footprint on pavement)
Both front tires measured 14/32
Both rear tires measured 13/32

Makes since to me that the rear will have more wear do to the weight applied from the trailer ( yeah, good reason to always rotate tires)

Looks like calculations are correct for proper PSI.

Now to my rant. If I am to inflate my tires to recommended max of 60psi:
1. Loss of control due to riding only on the center of the tire especially the front tires.
2. Premature wear of all tires.

I realize that not all drivers are as **** as I am about getting the proper psi, but please give us the option to go in and change the tolerances of the TPMS without expensive OBD scan tools or PIN numbers. The non **** drivers will follow the placard recommendations anyway, and I hope all goes well for them even though they may be white knuckled holding on to their steering wheel. I realize that there will be those that will disagree with me, but according with my placard on my RAM, they are dead wrong.
.
 

kevcarr59

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I've pulled our Grand Design 2600RB trailer consistently with the front truck tires at 65 psi & the rears at 70-72 psi. Trailer pulls rock solid, no sway, no white knuckles. I'd have to look on my phone to find my CAT SCALE ticket for some numbers. Okay, pulled em up:
Steer-- 3980#
Drive-- 5240#
Trailer- 7040#
Gross-- 16260#

This particular trip the bed was totally packed with kids tents, grill, various tubs & tools. The tongue weight on a scale is right under 1,000#. On the next trip I've raised the WDH trailer spring pads to increase weight transfer from the drive axle. According to the trailer sticker it states 80 psi COLD, but I normally run them at 72-75psi & the trailer rides perfectly fine and have never had any tire problems. I've done this set-up since last summer and pulling the trailer a total of almost 9,000 miles. I think my formula is working pretty good for me....
 

6.7CumminsDrvr

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Load inflation tables are great for this very thing, check out Toyo, they have a good one.

Goodyear Transforce LT 275/70/18 load range E with single load index of 125 have the following load capacity per tire:

3,640 lbs @ 80 psi
3,195 lbs @ 65 psi
3,020 lbs @ 60 psi
2,680 lbs @ 50 psi
2,470 lbs @ 45 psi
 

miles01

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I was so fead up with the factory settings on the 2500 having to have 80psi in the rear.
I bought the security bypass, OBDMX, and ALFAOBD program.
Not only did I change the thresholds for the tire pressures, but enabled fog lights to stay on with high beams, and fixed the mirrors to adjust with the trailer mirrors that were put on by the dealer (truck had regular mirrors)
The cost was more then worth it.
PS: I found the PIN number when using ALFAOBD you don’t need to go to the dealer to get it.
I don’t remember how I found it in the program.
I wrote the PIN number in my owners manual so I always have it.
 

P B Casterlin

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I just found this thread after a search. This is something that irritates both myself and my mechanic, not being able to change the TPMS through the settings menu. My 2018 2500 rides like a buckboard wagon with 80 psi in the rear.

How involved (and expensive) are the OBDMX and ALFAOBD programs? I really don't see using it for anything other than adjusting the TPMS thresholds.
 

P B Casterlin

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I just found this thread after a search. This is something that irritates both myself and my mechanic, not being able to change the TPMS through the settings menu. My 2018 2500 rides like a buckboard wagon with 80 psi in the rear.

How involved (and expensive) are the OBDMX and ALFAOBD programs? I really don't see using it for anything other than adjusting the TPMS thresholds.
 

retired

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I just found this thread after a search. This is something that irritates both myself and my mechanic, not being able to change the TPMS through the settings menu. My 2018 2500 rides like a buckboard wagon with 80 psi in the rear.

How involved (and expensive) are the OBDMX and ALFAOBD programs? I really don't see using it for anything other than adjusting the TPMS thresholds.
AEV procal will also do it. i use a procal snap because they changed on 19 and up but still similar devices.
0C554428-A421-42FF-936E-3AF6C93562D3.jpeg
 

P B Casterlin

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AEV procal will also do it. i use a procal snap because they changed on 19 and up but still similar devices.
View attachment 480227
Thanks for the info....looks like the module is around $200? It's Freakin' ridiculous that I have to spend $200 just to keep the TPMS light from flashing if a lower my tire pressure. How hard could it have been for Ram to include that in the settings menu. Makes me long for the days of my 1973 3/4 ton Power Wagon....
 

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