What is the correct PSI for these tires?

[ArmyRetCW3]

My first post here.

I recently bought a used 2021 RAM 1500 Limited with 3,650 miles. It did not have the original OEM tires = 275/55R20 113 BSW All Season Tires, with 20-inch x 9.0-inch polished wheels with inserts. I got this information from the MSRP sticker. It calls for a 36 PSI cold, for the OEM tires.

The tires on the truck are:
TOYO R/T OPEN COUNTRY - Tubeless Steel Belted Radial M+S 33x12.50 R20LT 114Q 10 P.R. - DOT 7 3 A 9 NKM0621 OPRT -B-A03
Never exceed 275??? (40 PSI) Load range E – Max Load 1180 kg (2600 lbs.) AT 450 KPq (65 PSI) cold

I went to the local Goodyear tire dealer about the correct PSI for every day driving, with no off-road driving. He recommended to keep it at around 38 PSI, which is within the 40-65 PSI. However, I also sent an email to the TOYO tire company thru their web site and the response was to keep it at 55 PSI. Still within the limits but a bit higher than the 38 PSI from the Goodyear guy.

What is the correct PSI for these tires? Thank you in advance.

 

[Rlaf75]

I run 40psi in every tire on every vehicle I have ever owed and I never had a problem. I've always gotten great mileage out of each set of tires on all of them with proper rotations at reasonable intervals. I would recommend picking a pressure within that range and start with that. Drive it for awhile and see how it feels and adjust accordingly until you find your comfort zone. Dont over think it

 

[SKT Customs]

I would run about 40 in the front and probably 35 in the back (unloaded) if I were you.

 

[Nels]

I asked the same question of bf Goodrich when i put bfg KO2s on. They wouldn't give me an opinion.

 

[djevox]

I agree with the other guys on here and will say that this is not a permanent decision. This question is mostly opinion based, and that’s why answers will be all over the place once this thread grows. Now that I’ve said that, I’ll add my opinion.

i’ve always Inflated to within 4-5 psi of the max inflation on the side of the tire. For LT tires, there are some vehicles that call for the rears to have a max inflation rate of 80psi (matches the sidewall psi). From filling thousands of those tires in my younger days to max inflation rate, I’m confident that what the manufacture puts as the max cold psi on the side of the tire is safe and that is for all ratings of tire.

I have the LT version of the open country, and I noticed that I had to inflate pretty highly to get decent performance out of them. I also noticed that they were cupping when they were inflated to 50 psi (max is 80). I’m saying that because while you’re playing around with air pressure, you’ll need to watch your tires for cupping or ballooning.

 

[BowersFJ]

I ran Toyo OC ATll on my 2012 …. 35” X 12.50’s …. 42 F. 40 R …. They wore great, rode great, and I got 55k miles out of them …. 65 is for a fully loaded condition …. Unloaded at 65 it will ride like sh!t, and wear the center of the tread …. JMO


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[Nick57]

Ok I'm going to give you an answer to this and the reason why it's the CORRECT answer. The sticker on the inside of your drivers door jam gives you the recommended PSI they want the tires to be at on the vehicle. It does NOT matter the size tire that is on there or the max PSI the tire can handle(the max PSI a tire can handle does matter and I will get to that.) Just because the volume of air changes when a tire size is different doesn't mean the pressure (PSI in this case) to maintain the design (shape) will. Now this is true for a radial to radial, if you go from radial to bias that's a different tire construction and then would require a different PSI to maintain the correct shape for that vehicle. As far as the max PSI rating on a tire... lets say a tire has a max PSI rating of 65. For most vehicles you'll still be only running these between 32-40 PSI and will work and function as designed. How ever on a lot of 3/4 and 1 ton trucks the rear PSI the manufacturer of the vehicle recommend is 80 PSI. So those 65PSI max rated tires will not work for those vehicles you would need a tire with a 80PSI max. You can run a 80PSI max tire on your 1/2 ton and be just fine doesn't hurt anything but you'll be running it at 32-40PSI (depending on the door sticker and situation) not 80PSI. I hope I was able to clear this up for some. I've been in the industry for 25 years now and work at 4WP. So I'm very familiar with changing tire sizes and types on vehicles. If you have any questions please feel free to message me or tag me in a post here. Thanks

 

[ferraiolo1]

The sticker on the inside of your drivers door jam gives you the recommended PSI they want the tires to be at on the vehicle. It does NOT matter the size tire that is on there or the max PSI the tire can handle(the max PSI a tire can handle does matter and I will get to that.)

The sticker inside the door tells you the recommended pressure for the Oem tire that came on that particular truck.

These trucks come with different size and different rated tires, and the door jam psi recommendation changes. Based on the tire. Not the vehicle.

If you change the tire rating different than what comes on the truck Oem, then the psi on the door sticker becomes irrelevant

Running 36psi in my LT toyos made them ride like crap, thus bumping the pressure closer to 45psi. That’s usually why you consult the tire manufacture for a recommended pressure when installing a non Oem type/rating/size tire on your truck


Op run between 40-45 psi in those.

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[SD Rebel]

Actually, if you call the manufacturer of the tire, they almost always recommend whatever is on the door plaque on the vehicle, probably for liability concerns.

I've seen RAMs of various trims and different size tires with the same PSI rating on the door decal.

It makes sense that a different tire would require a different PSI, but I've been told many times with both tire shops and tire makers to go with the door plaque. To that end, I don't know the actual answer, it could be tire manufacturers kicking the can to avoid any liability should a tire failure happen.

Me personally, my truck has the 55F / 45R recommendation, I personally run 51F / 41R, I would actually run lower if it didn't set off the TPMS warning.

 

[ferraiolo1]

And non rebels are around 36psi.

Same vehicle. Different tire rating

If you ran lower the tires would wear oddly and ride / vehicle control would suffer.


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[SD Rebel]

And non rebels are around 36psi.

Same vehicle. Different tire rating

If you ran lower the tires would wear oddly and ride / vehicle control would suffer.


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True, though the springs are differently sprung as well on the Rebel. Though I wonder what is the PSI recommendation on any RAM with the ORP, which I think has the same springs and shocks as the Rebel?

However, I've seen two different Laramies for example, both with completely different tire and wheel packages with the same 36 psi.

 

[ferraiolo1]

Because the rating of the tires is the same in on them, brands/sizes can vary. They are more of a passenger tire than a truck tire.

The springs and suspension package is irrelevant.


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[SD Rebel]

Because the rating of the tires is the same in on them, brands/sizes can vary. They are more of a passenger tire than a truck tire.

The springs and suspension package is irrelevant.

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Within OEM tires sure, that doesn't actually explain why tire manufacturers will tend to always recommend the door decal regardless of which one of their tires you are using, which likely won't match exactly what the OEM tires were.

Springs and suspension package is not irrelevant, it could determine what tires OEM wants to use which can determine a change in tire pressures. I guess a good way to tell, at least within a model trim, lets say a Laramie Crewcab 4x4, one with an ORP package and one with a sport package, what tire pressures they recommend on the door sticker? My guess is they will be different.

 

[ferraiolo1]

They will be the same if they have the same rated tire, which sometimes they don’t since the off-road packages usually get a more heavy duty tire, aka the rebel, not always because of the springs or suspension.

And technically you’re not supposed to deviate from the Oem size type tire that came on the vehicle. Which is why some people you talk to Just refer you to the Oem spec on the door sticker to avoid any type of liability. And why some dealerships won’t install any size tire that’s different than Oem spec for that particular vehicle.

This is nothing new, it’s the same for motorcycles and cars.


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[SD Rebel]

Sure, that pretty much matches what I was talking about. I think we have similar opinions, just explaining them a little differently and coming up with the same conclusions.

 

[ferraiolo1]

Say you wanted to stick a set of Oem wheels And tires off a Laramie sport on your rebel, you wouldn’t run them at 50psi. You would run them at 36. That’s what I meant by suspension being irrelevant


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[SD Rebel]

Say you wanted to stick a set of Oem wheels And tires off a Laramie sport on your rebel, you wouldn’t run them at 50psi. You would run them at 36. That’s what I meant by suspension being irrelevant


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Sure, that makes perfect sense to me. Though if I ask the tire manufacturer, they will tell me to go with my sticker, which I know isn't right.

However, I also don't want to get a warning light on my dash because I'm way below the original set pressure. It's fine when off-roading and aired down, but not something I want to look at all the time.

I can get a tuner to fix that, but worried it will somehow get my warranty denied by the dealer. This is the dilemma of aftermarket tires on these trucks, and probably other manufactures.

 

[Nick57]

Sorry to come off as a jerk by this next statement. To the people who are disagreeing with my post; where are you getting your information from, what training have you had, are you in the automotive field that deals with lifted/non lifted trucks/jeeps ect... ? Or are you going your info off your buddy,mom,dad,wiki,youtube,bathroom stall door....

 

[cervelo15]

What I learned on this forum was the chalk test....color a cross section of each tire with chalk and find a flat surface.....drive 75-100 yards in a straight line....backup in a straight line.....get out and check how the chalk wore off the tread.

If it wore off just in the middle, its overinflated. If it wore on the edges of the tread only and didnt touch the center of the tread, its underinflated.

I did this sort of on my driveway, but the results were a little skewed since it slopes slightly away from the garage. At any rate, I found that through driving feel and the half-azz chalk test I did, 39.5 was the best PSI.

I may tweak it a little more, but im right in that 40-45 range.

 

[SD Rebel]

Sorry to come off as a jerk by this next statement. To the people who are disagreeing with my post; where are you getting your information from, what training have you had, are you in the automotive field that deals with lifted/non lifted trucks/jeeps ect... ? Or are you going your info off your buddy,mom,dad,wiki,youtube,bathroom stall door....

What disagreement in particular, I think everyone is pretty much saying the same thing.