Tire pressure

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Brhodes

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Does this seem correct to you guys on nitto ridge 37x13.50r22’s?e7758ebb11f64e755e25ac80d0bf5798.png


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Litos

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I just got done reading 4 different tire pressure links that say 65psi is the Max tire psi for Nitto LT325/50/22 122S...

my TPMS light came on and it says I had 31, 34, 32 and 33...

It doesn't matter which tire has what PSI, I was just more concerned seeing I was WAAAYYYY OFF the recommended PSI for this sized tire...

I would think your size would be around the same, if not pretty much identical...

https://tirepressure.com/nitto-terra-grappler-g2-tire-pressure
 

Litos

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So people really inflate these 35's up to 60psi ?? :eek:
 

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So people really inflate these 35's up to 60psi ?? :eek:
Yes I see it every day people driving around on rocks. LOL
 

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Does this seem correct to you guys on nitto ridge 37x13.50r22’s?e7758ebb11f64e755e25ac80d0bf5798.png


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Being that you have a 2500 those numbers are pretty close. What motor do you have?
 

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Just noticed this is an old thread
 

Litos

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Just noticed this is an old thread
It's ok...

Im a seasoned forum guy over the last 18 years and I know better than to start a new thread hahaha !!!

I know how to do the whole search thing - anyways, I'm probably just going to run 50psi on all 4 corners...

thoughts ??
 

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It's ok...

Im a seasoned forum guy over the last 18 years and I know better than to start a new thread hahaha !!!

I know how to do the whole search thing - anyways, I'm probably just going to run 50psi on all 4 corners...

thoughts ??
I can’t tell from your profile pic looks like you have a 1500 which you would be running in the 35 psi range
 

Litos

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I can’t tell from your profile pic looks like you have a 1500 which you would be running in the 35 psi range
Yes sir - 14 Ram 1500

I was in the range before I read the recommended PSI for 35's, so I jacked it up to 50...

ughghgh....
 
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I am running 36psi in the rear and 41psi in the front on my 37x12.5R20s on my 1500 .... with 36psi in the rear the rear end stays on the ground just right with the front giving me really good handling ...

I would not go anywhere near 50 and 40 with these tires ... having worked at a tire shop for 5 years helped me see what is a good tire pressure depending on the tires and vehicles they go on ...

And also remember, rotating your tires every 3k-4k with tires 35 and bigger will help keep them fresh for a long time ...
 

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Yes sir - 14 Ram 1500

I was in the range before I read the recommended PSI for 35's, so I jacked it up to 50...

ughghgh....
Yes tire pressure doesn’t care how big your tires are. It’s requires more air to reach desired psi but many mistake that for they need more pressure. Most bigger tires are e rated or thicker side walls so they are more capable to air way down for off-roading
 

Litos

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Yes tire pressure doesn’t care how big your tires are. It’s requires more air to reach desired psi but many mistake that for they need more pressure. Most bigger tires are e rated or thicker side walls so they are more capable to air way down for off-roading
Ok, so here's the million dollar question

why would Nitto recommend almost more than double the psi that most are running ??

mid there a clear answer on that, or is it more murkiness ??
 

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Ok, so here's the million dollar question

why would Nitto recommend almost more than double the psi that most are running ??

mid there a clear answer on that, or is it more murkiness ??
Are you referring to nitto’s max psi? the OP had a 2500 which is heavier then our 1500. Also inside your door is a sticker recommending tire PSI.
If you tow you would want to inflate your rear tires while towing but fronts generally stay the same. If you want optimal tire wear then you would do “the chalk test” that is when you put chalk on the treads and drive 25’ and look at the wear. Then adjust psi and repeat. I recommend to everyone to set it to the numbers printed on the sticker inside the drivers door to start then adjust from there. I’m at 38 front 34 rear with a 325/60 tire which is a very big 35 they would generally class with a 37 as they measure the same as most 37’s
 

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I am running 36psi in the rear and 41psi in the front on my 37x12.5R20s on my 1500 .... with 36psi in the rear the rear end stays on the ground just right with the front giving me really good handling ...

I would not go anywhere near 50 and 40 with these tires ... having worked at a tire shop for 5 years helped me see what is a good tire pressure depending on the tires and vehicles they go on ...

And also remember, rotating your tires every 3k-4k with tires 35 and bigger will help keep them fresh for a long time ...


I'm running these same numbers on 35's with a great ride and perfect wear........ 2018 1500 2wd
 

Litos

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Are you referring to nitto’s max psi? the OP had a 2500 which is heavier then our 1500. Also inside your door is a sticker recommending tire PSI.
If you tow you would want to inflate your rear tires while towing but fronts generally stay the same. If you want optimal tire wear then you would do “the chalk test” that is when you put chalk on the treads and drive 25’ and look at the wear. Then adjust psi and repeat. I recommend to everyone to set it to the numbers printed on the sticker inside the drivers door to start then adjust from there. I’m at 38 front 34 rear with a 325/60 tire which is a very big 35 they would generally class with a 37 as they measure the same as most 37’s
Yeah, for my LT325/50/22 122S, Nittos says max tire pressure of 65psi for a 1500...

I'm at 50psi on both fronts right now, but that was my question: why would Nitto say 60-65psi for a 1500 ??

looks like it doesn't really matter what tire size you got, people are just sticking to the psi dictated on the door :cheers:
 

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figure it out by using the tire info on the sidewall and the weight of your truck. Side wall says how much weight it can support at max air pressure. Take an educated guess at how much weight each tire actually has too supports and do the math.
 

Litos

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figure it out by using the tire info on the sidewall and the weight of your truck
That's what I did, and that's what triggered my question

sidewall for my Nitto Terra Grapers is LT325/50/22 122S and they are on a Ram 1500...

...based on 3 or 4 different sites (including Nitto), I see max tire pressure of 65psi...

as of tonight, both front tires are hovering around 49/50, depending on how cold it gets at night...
 

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It may say 65 but at what weight , thats written right next to the psi on the tire. Figure out what weight you are dealing with and playing with the sidewall info and what your truck weighs on front and rear axles and calculate . Its not an exact science but will get you in the ball park if you have nothing else to go by . I just start with what the door says and adjust to my liking from there no matter what size tire I just installed. The Mfg will usually tell you a high amount to protect them from people who have no clue. I run the front at about door psi to 1 below and rears about 1.5lbs less than the front. I struggle because I hate 20" wheels and normally sell them and replace. with 17" aftermarket
 

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I ran my KO2's D rated 37x12.5x17 at 32 psi. at that PSI they can actually hold more weight than what the door says to run at 39psi on the factory P 275/60/20, at such PSI the max load per tire will be 2601lbs per tire, which in a P tire is attained at 35 psi, i guess the factory says 39 to maximize MPG ? so if you wanted to match what the factory did with 325/50/22 just looking the tra table at what PSI that tire can hold 2601lbs.
So do a little math, at 45 PSI the tire is rated for 2550lbs, 2755lbs at 50 psi. So that means 2755-2550/5=41lbs per each increment from 45 psi to 50 psi, thus you need 47psi to exceed 2601lbs.

there is also another rule per TRA guidelines that says if the truck was equipped with P rates the load can b reduced 10% when you move to LT, so you don't need to match 2601lbs, but 2601*10%=2341lbs, so you could go as low as 40 PSI to exceed that value and still be able to support 2341x2+*2=4682lbs from both tires, which exceeds your GAWVR of 3900lbs max so I'll set them at 40psi and call it a day. per Tra table that would be 2350lbs per tire, x2 = 4700lbs which again is way above your 3900lbs GAWVR

upload_2020-12-10_12-39-0.png
https://www.toyotires.com/media/2125/application_of_load_inflation_tables_20170203.pdf
 
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El_Lobo_Gris1500C

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Are you referring to nitto’s max psi? the OP had a 2500 which is heavier then our 1500. Also inside your door is a sticker recommending tire PSI.
If you tow you would want to inflate your rear tires while towing but fronts generally stay the same. If you want optimal tire wear then you would do “the chalk test” that is when you put chalk on the treads and drive 25’ and look at the wear. Then adjust psi and repeat. I recommend to everyone to set it to the numbers printed on the sticker inside the drivers door to start then adjust from there. I’m at 38 front 34 rear with a 325/60 tire which is a very big 35 they would generally class with a 37 as they measure the same as most 37’s
Do you get dash lights/TPMS alarms running at 35 & 38 PSI?

My dash was giving warnings when two new tires went down to about 30-32PSI, but was ok when they were around 35 - 38 PSI. New tires so I didn’t get the chance to check inflation until Inwas in the work shop with my digital tire inflator. But it’s also been around -15 to -20 C here the last few days so that’s probably thrown everything off.

Finally set them to 42 PSI as per the caculator online (vs or using my stock 20” OeM tire door sticker at 39 PSI info) now running the E LT 35” Toyo’s. I’ll use this as a starting point and get to that tire chalk test as soon as it dries up enough to do that.

Just wondering though, if I end up doing that chalk test and it shows that around 32 to 35 PSI is ideal, will I have the dash consistently annoying me with warnings?
 
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