Optimal Tire Pressure

[PyrPatriot]

How do you determine what the maximum tire pressure is? I know the mfg has a maximum cold tire pressure but surely you dont want to run at max pressure all the time?

My Falken Wildpeak M/T load range C tires have a max pressure of 50psi, but when loading the truck down or towing that would increase.

Apparently there is a way to calculate it based on vehicle weight?

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[Oscar Indy]

How do you determine what the maximum tire pressure is? I know the mfg has a maximum cold tire pressure but surely you dont want to run at max pressure all the time?

My Falken Wildpeak M/T load range C tires have a max pressure of 50psi, but when loading the truck down or towing that would increase.

Apparently there is a way to calculate it based on vehicle weight?

The max pressure of 50 will never increase.
That is the tires max. When you look at the tire spec it's load carrying capacity is at that psi. For example if your tire supports 3500lbs then at 50psi it's capable of supporting that weight. When it's on the unloaded truck you need a fraction of that weight. Say the truck weights 6000 lbs. Each tire only needs to support 1500lbs. That is roughly 42% of it's load capacity. Add 10% for safety buffer and you are at roughly 50% of the tires capacity which would be 25psi.

As you add weight this math can be redone to get you close to the ideal pressure.

But a chalk test is better.

 

[Renegade]

There are a lot of differing opinions on appropriate tire pressures. Short answer is to use what is on the door jamb.

 

[Oscar Indy]

There are a lot of differing opinions on appropriate tire pressures. Short answer is to use what is on the door jamb.

If you have factory tires. Even then it's often not ideal for added weight

 

[ShadowsPapa]

There are a lot of differing opinions on appropriate tire pressures. Short answer is to use what is on the door jamb.

Have always done just that - and tires always have worn perfectly true. My Chevy truck at 47,000 miles and towing all over the place - tires were evenly worn straight across.
When I did some digging into what was on the door jamb of our vehicles, including the Chevy and other vehicles I have the tire makers recommending nearly the same numbers. Tire makers don't care about CAFE numbers.
When I had tires repaired - when I got them back they were inflated to numbers pretty well matching what we had always used with that vehicle. (they went by the tire maker recommendation I found - like I used to when I worked selling and repairing tires)

 

[PyrPatriot]

Have always done just that - and tires always have worn perfectly true. My Chevy truck at 47,000 miles and towing all over the place - tires were evenly worn straight across.
When I did some digging into what was on the door jamb of our vehicles, including the Chevy and other vehicles I have the tire makers recommending nearly the same numbers. Tire makers don't care about CAFE numbers.
When I had tires repaired - when I got them back they were inflated to numbers pretty well matching what we had always used with that vehicle. (they went by the tire maker recommendation I found - like I used to when I worked selling and repairing tires)

Doesnt the door jam only apply to the oem tires? Surely 31.5” highway tire shouldnt have the same psi as a 33” mud tire

 

[Oscar Indy]

Doesnt the door jam only apply to the oem tires? Surely 31.5” highway tire shouldnt have the same psi as a 33” mud tire

The door pressure is for the factory equiped tire. Any change in size, capacity or load rating will require a different psi. Some are close enough it doesn't matter. Others like putting a D or C rated tire on are going to be drastically different.

For example I run a D rated 37. My optimal pressure is 26 cold.

 

[Renegade]

Doesnt the door jam only apply to the oem tires? Surely 31.5” highway tire shouldnt have the same psi as a 33” mud tire

There’s just so more to it, that there isn’t an easy answer. Tire size, load range/rating, vehicle weight/load, etc. all play in. There isn’t a one-size fits all answer, so that’s why I just said “door jamb”. That will put you in a safe place for pretty much anything anyone is doing on the road, within ratings.

 

[RH 67]

The door jam is only for the OEM tires. Example my Ford F-250 SD says 80psi rear and 74psi front, replaced the OEM tires wit 37" Toyo MT`s that have a maximum psi of 50. Max psi is for the maximum load range anyway which the Toyo`s can handle at 50psi, if your not hauling or towing you do not want to be near the max psi the door jam is only referring to what the tires can handle at max psi and not what psi you should be at without that max load.

 

[Seansmd]

The door jam is only for the OEM tires. Example my Ford F-250 SD says 80psi rear and 74psi front, replaced the OEM tires wit 37" Toyo MT`s that have a maximum psi of 50. Max psi is for the maximum load range anyway which the Toyo`s can handle at 50psi, if your not hauling or towing you do not want to be near the max psi the door jam is only referring to what the tires can handle at max psi and not what psi you should be at without that max load.

So is the 37psi accurate for the OEM tires on my Glad_Rubi with OEM 33's?

 

[ShadowsPapa]

So is the 37psi accurate for the OEM tires on my Glad_Rubi with OEM 33's?

It's been spot on for mine and for my wife's JGC. My truck - Silverado and the Ford before that, hauled loads, trailers and so on and the tires lasted and wore very evenly- I followed the book.

If you want the facts and expert advice - find a tire DEALER that knows their products. Don't speak with the kids that have worked there 2 weeks.
We knew tires inside and out (I used to sell and repair tires in one of my first jobs, then when working my way through college doing front ends, alignments, and tires).
We knew the pressure, expected life, which was best for this or that, load ratings, how full to fill them for various uses and vehicles. In short we could be pretty accurate for tires we sold and knew how much pressure to run them based on the typical weight of vehicles - and advised the owners more for more payload, towing, and so forth. Things have changed, obviously, I'm no expert on today's offerings and have other things I prefer to deal with.
I've had great results from a dealership I've used lately for tires for my things. Funny thing is last two times I've taken tires in for repair I got the tires back with the same psi in them that the door stickers said to run - within a couple psi anyway, and I never took the vehicle to them, only the tire!
Maybe it's a thing of the past but we knew our tires, and how full to run them based on vehicle and load. And when customers came in with unusual wear - we had to deal with it.

Talk to the TIRE EXPERTS that sell THAT tire and know THAT tire. Load ratings, how tall, how wide, vehicle weight, etc. - there's no one answer fits all in most cases.
I run what the tire maker says and move from there based on wear and load. In many cases what the tire maker recommends is what's on that vehicle because it's the tire people that have to support the tire and the tire people don't give a bloody rip about CAFE numbers. They have to warrant your tires.

 

[PyrPatriot]

It's been spot on for mine and for my wife's JGC. My truck - Silverado and the Ford before that, hauled loads, trailers and so on and the tires lasted and wore very evenly- I followed the book.

If you want the facts and expert advice - find a tire DEALER that knows their products. Don't speak with the kids that have worked there 2 weeks.
We knew tires inside and out (I used to sell and repair tires in one of my first jobs, then when working my way through college doing front ends, alignments, and tires).
We knew the pressure, expected life, which was best for this or that, load ratings, how full to fill them for various uses and vehicles. In short we could be pretty accurate for tires we sold and knew how much pressure to run them based on the typical weight of vehicles - and advised the owners more for more payload, towing, and so forth. Things have changed, obviously, I'm no expert on today's offerings and have other things I prefer to deal with.
I've had great results from a dealership I've used lately for tires for my things. Funny thing is last two times I've taken tires in for repair I got the tires back with the same psi in them that the door stickers said to run - within a couple psi anyway, and I never took the vehicle to them, only the tire!
Maybe it's a thing of the past but we knew our tires, and how full to run them based on vehicle and load. And when customers came in with unusual wear - we had to deal with it.

Talk to the TIRE EXPERTS that sell THAT tire and know THAT tire. Load ratings, how tall, how wide, vehicle weight, etc. - there's no one answer fits all in most cases.
I run what the tire maker says and move from there based on wear and load. In many cases what the tire maker recommends is what's on that vehicle because it's the tire people that have to support the tire and the tire people don't give a bloody rip about CAFE numbers. They have to warrant your tires.

What if the tire maker doesn’t recommend anything?

 

[Seansmd]

It's been spot on for mine and for my wife's JGC. My truck - Silverado and the Ford before that, hauled loads, trailers and so on and the tires lasted and wore very evenly- I followed the book.

If you want the facts and expert advice - find a tire DEALER that knows their products. Don't speak with the kids that have worked there 2 weeks.
We knew tires inside and out (I used to sell and repair tires in one of my first jobs, then when working my way through college doing front ends, alignments, and tires).
We knew the pressure, expected life, which was best for this or that, load ratings, how full to fill them for various uses and vehicles. In short we could be pretty accurate for tires we sold and knew how much pressure to run them based on the typical weight of vehicles - and advised the owners more for more payload, towing, and so forth. Things have changed, obviously, I'm no expert on today's offerings and have other things I prefer to deal with.
I've had great results from a dealership I've used lately for tires for my things. Funny thing is last two times I've taken tires in for repair I got the tires back with the same psi in them that the door stickers said to run - within a couple psi anyway, and I never took the vehicle to them, only the tire!
Maybe it's a thing of the past but we knew our tires, and how full to run them based on vehicle and load. And when customers came in with unusual wear - we had to deal with it.

Talk to the TIRE EXPERTS that sell THAT tire and know THAT tire. Load ratings, how tall, how wide, vehicle weight, etc. - there's no one answer fits all in most cases.
I run what the tire maker says and move from there based on wear and load. In many cases what the tire maker recommends is what's on that vehicle because it's the tire people that have to support the tire and the tire people don't give a bloody rip about CAFE numbers. They have to warrant your tires.

Makes sense that they have to size that for typical use, more than one passenger, some load. We air down/up for the trails but very few ever adjust their tires for other reasons, trips, extra pasengers, etc.

 

[ShadowsPapa]

What if the tire maker doesn’t recommend anything?

Good dealers that don't just "sell tires" will know where to start or what's typical for a given use and load if you can't find a manufacturer's suggested pressure
Many cars and trucks I've bought over the years have a booklet from the tire maker, like Goodyear, Bridgestone/Firestone, whatever, that tells where to get specifics, often including specifics for the tires that vehicle may come with. My Chevy had a fair booklet about the tires on it.

 

[PyrPatriot]

Good dealers that don't just "sell tires" will know where to start or what's typical for a given use and load if you can't find a manufacturer's suggested pressure
Many cars and trucks I've bought over the years have a booklet from the tire maker, like Goodyear, Bridgestone/Firestone, whatever, that tells where to get specifics, often including specifics for the tires that vehicle may come with. My Chevy had a fair booklet about the tires on it.

You inspired me to look deeper. Falken didnt have a tire pressure chart on their product page but it was in their warranty/maintenance section. Looks like my 255/75/17 M/T tires can go from 35-50psi, currently at 40 from the dealer and rated for a little over 2000lbs each at that point. Plenty for the JT. Cant wait to try them out in some mud/snow

https://www.falkentire.com/tires/care-safety-warranty

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