Tire PSI Question

[Spree]

2017 Ram 1500 Big Horn 5.7.
The question is: My stock tires are 275x60x20 44psi (33's) and I want to change them to 295x65x20 80psi (35's) on my next set which is soon.
Will my TPMS go off for too much pressure? If so, how do you guy's fix this so you don't get the warning when going to a bigger tire that requires more pressure?
I am running a 2" lvl with no wheel spacers.

 

[DA67Goatman]

First off, the factory 1500 wheels are only rated to 50psi so you should be weary about running any higher. Secondly, the tire is rated for max load at max pressure, you do not need maximum load of that tire on your half ton truck so start with the same pressure you are already running and adjust from there based on the tire wear pattern and personal preference. I regularly run 33psi in my 275 65 and have bumped them up when towing to 45psi.

 

[Bigskyroadglide]

I'm running 315 70 17 essentially 35s at 46 psi and it's higher than I would like. I would like to do 40 but they feel real soft at 40. No way I would ever run 50 or higher

 

[rzr6-4]

a bigger tire that requires more pressure?

Bigger tires take LESS pressure. I have 18" wheels but otherwise similar size, I run 35-ish psi. When I first got them mounted I filled them to 45 I think and they were awful.

 

[Jeepwalker]

I wonder if a guy changes the tire-size in the truck's computer, to the larger tire ...if it adjusts for a different or wider pressure range? Just thinking out loud.

Maybe someone will chime in with their experiences.

 

[EdGs]

I had Cooper Discoverer A/T's that I got from WalMart. They were LT265/70R17 and were "E" rated 80 psi max.

I ran them 45 to 50 psi and never got a warning, but I never had cause to air them up more. They were awesome tires, I got 81k miles out of them. Plus, at that time, I got a set of 4 for ~ $675.




Since then Goodyear bought Cooper so I cannot vouch for the quality there. I do have a set of the corresponding 'new' model on our '13 Tundra XSP-X in 275/55R20, so we will see how durable they are.

 

[CanuckRam1313]

I currently run Michelin LTX M/S in LT295/65R20 (equivalent to 35's) on my stock 20x9 Warlock rims for my summer set up.
Michelin's warranty is also second to none as well.

I keep them at 40psi (cold checked and adjusted) and the ride is excellent and so is the wear (perfect, symmetrical, flat, and full road contact, too).

Unless I'm hauling or towing I keep them at 40psi, and if I am doing either, I'll pressure up to 50psi as a maximum pressure.

For me personally, I prefer an LT Rated tire, and the Load E rating on these Michelin's is nice peace of mind.
They are more rugged and stable vs a standard P-Metric tire (like the garbage good-for-a-year RSA OEM tires our trucks typically come with).

These specific tires are a dream to balance up (always opt for Road-Force-Balancing as well, especially on an LT tire) and require very little weight.
Two of my tires took .25oz, one took .5oz, and the last was .75oz.

Whereas the BFG KO2's I had before took in excess of 10oz per tire, and they weren't great in wet road conditions either.
Those were LT285/65R20 - Load E rating and they were almost 6lb heavier per tire compared to the slightly larger Michelin's I have now.

 

[turkeybird56]

I just run 275 65R 18s on my Bighorn. But than I am mostly stock. Got Falken AT3s mspf tires which I cold air to 37.5 psi. 36 a lil soft. But it gets real hot here and air in tires will heat up to 40/41/42 when running. These Falkens are C rated tires not need E rated.

Posting for the regular guy not running bigger oversized rubber.

But I would run anything than sorry SRAs.

 

[Spree]

Thanks guy's, I was planning on going with Cooper SST's this time. I'll just keep them around 40 just like I do with my Cooper Rugged Trek's.

 

[62Blazer]

You may have already figured it out, but a quick explanation.
The PSI shown on the side of the tire is the maximum pressure those tires are rated for. It is not the recommended or required PSI for all conditions. The tires with a higher maximum PSI are generally meant for much higher loads (such as a 3500 hauling heavy loads) and need that higher PSI to support the weight. If you put an 80 PSI max tire on a 1500 that originally had tires with a 44 or so max PSI you can run the 80 psi tires down in the same 44 PSI pressure range. You do not need the added weight capacity that the higher PSI provides by any means.

 

[crash68]

I wonder if a guy changes the tire-size in the truck's computer, to the larger tire ...if it adjusts for a different or wider pressure range? Just thinking out loud.

Unfortunately it doesn't work that way, the TPMS are separate settings from the tire diameters.
I believe the TPMS warning pressure set points can be changed with AlfaOBD.

 

[62Blazer]

I wonder if a guy changes the tire-size in the truck's computer, to the larger tire ...if it adjusts for a different or wider pressure range? Just thinking out loud.

Maybe someone will chime in with their experiences.

Changing the tire size calibration in the computer is separate from changing the pressure thresholds of the tire pressure monitor system. If you change the tire size calibration that will affect the speedo, odometer, trans shift points, etc.... but does nothing to the tire pressure system. Typically you can go in separately and adjust the TPMS settings. The main reason for that is the tire size and the max tire pressure are not directly related to each other. For example you can get the exact same size and brand of tire in different load ratings, and those different load ratings have different max PSI settings. For example you can get a 35x12.50R17 BFG KO2 in either a C or D load range which have different max PSI ratings.

 

[RamDiver]

Unfortunately it doesn't work that way, the TPMS are separate settings from the tire diameters.
I believe the TPMS warning pressure set points can be changed with AlfaOBD.

I've heard that some users require the PIN code to update tire pressure thresholds, but hearing mixed reports.

I have not tried this tweak yet, but I will try it out soon.

AlfaOBD/Body Computer/Update Pressure Thresholds
Pressure settings available 10 - 80 PSI





The PIN code is available with AlfaOBD while connected to the RF module, but again, hearing mixed reports depending on the year of the truck.

My understanding is that the PIN code is only required to program new FOBs, but I don't have experience with that.

This post claims that any truck 2019+ the PIN uses a rolling code only available from a stealership.

.