Tire Pressure

[Ratman6161]

I don't know how you guys can run lower than 70 psi in rears, cause one of the software "upgrades" throws an alarm below that. Previous software was 60 psi. The official FCA reasoning was "truck is designed for that".

My ass - the lawyers mandated it to dummy-proof from owners forgetting to air up when loaded.

That isn't how mine works. In fact my previous 2500 bighorn the pressures according to the door sticker was supposed to be 60 front and 65 rear and I ran them as low as 55 without any kind of alarm. I found a pressure chart online for the Firestone tires that said that at 65 psi, the load carrying capacity of the tire is 3195. 3195 x 2 tires = 6390 which not coincidentally is the GRAWR for the rear axle. So the suggested 65 psi probably is making it dummy proof...but I've never se.n an alarm when running under 65. What I can't figure is why my new Laramie with the same tires and same axle weight ratings has a sticker that says 70 psi.

 

[HEMIMANN]

Who knows?

Can't see your model year, mine is 2017.
I had half a dozen recalls, one of which they added tire pressure alarms for 80 psi full time regardless of load.

Worse, it was not listed in any of the recalls. Some weasel added it to all software updates. I complained to the Service Manager to no avail.