What psi are you running your 37s??

[Medsker]

I run 30 psi in my 37" BFGoodrich KM3's. They have 36,000 on them and they are wearing even across the tread.

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[kapk22]

How are you liking those tires? Can you compare them to any other tires you had before?
I’m searching around for some 37s now. Also, could you pretty please post your actual mounted height measurement on here? Thank you!!

total height I am seeing to the top of the hard top is 77 1/2”

I ended up with just under 4” of lift up front and 3 1/4 “ in the rear from the Mopar 2”.

 

[MichaelAnthony]

running Coopers 37x13.50x17 E rating and running 24 psi and feels good. I run 10 psi on the trails

 

[Living Good 357]

running Coopers 37x13.50x17 E rating and running 24 psi and feels good. I run 10 psi on the trails

Those are the same size tires I'm thinking about running, can you please post a photo? How wide of a wheel are you running? Thanks

 

[Gotcha-Again-LOL]

I am running 26-28 psi in mine. 37/12.5/17 BFG KM2 Load Range D...they hold so much weight per tire you need to run lower pressure to not beat yourself up also too high psi will cause wandering on the Highway as well.

 

[kapk22]

I am running 26-28 psi in mine. 37/12.5/17 BFG KM2 Load Range D...they hold so much weight per tire you need to run lower pressure to not beat yourself up also too high psi will cause wandering on the Highway as well.

Those are the same size tires I'm thinking about running, can you please post a photo? How wide of a wheel are you running? Thanks

Maybe I will drop down a little more.

 

[kapk22]

I am running 26-28 psi in mine. 37/12.5/17 BFG KM2 Load Range D...they hold so much weight per tire you need to run lower pressure to not beat yourself up also too high psi will cause wandering on the Highway as well.

Holy cow!

I dropped them down to 27 and the it made a huge difference in the ride. Did not think a few pounds would make such a difference.

Odd thing is, I dropped them with a small manual handheld gage and the dash still shows 30-31. Regardless, I am happy.

I did notice the mud grapplers are a little quieter than they were when they were up at 38-40, which kinda bums me out (I like the noise).

Thanks guys.

 

[Gotcha-Again-LOL]

Holy cow!

I dropped them down to 27 and the it made a huge difference in the ride. Did not think a few pounds would make such a difference.

Odd thing is, I dropped them with a small manual handheld gage and the dash still shows 30-31. Regardless, I am happy.

I did notice the mud grapplers are a little quieter than they were when they were up at 38-40, which kinda bums me out (I like the noise).

Thanks guys.

Awesome!!!!!

 

[Arterius2]

Holy cow!

I dropped them down to 27 and the it made a huge difference in the ride. Did not think a few pounds would make such a difference.

Odd thing is, I dropped them with a small manual handheld gage and the dash still shows 30-31. Regardless, I am happy.

I did notice the mud grapplers are a little quieter than they were when they were up at 38-40, which kinda bums me out (I like the noise).

Thanks guys.

27 on Load range D? oh wow.

PSI is PSI, shouldn't change just because you are running larger tires, especially at Load Range D, which means softer side walls than load range E.

Also, you should actually be able to run higher pressure with lager tires because there are more total sidewall rubber to compress than smaller tires.

Then again, people tend to get angry whenever I talk about science and facts.

So I'll stop.

Glad it works out for you though, and it look really good!

 

[Gotcha-Again-LOL]

27 on Load range D? oh wow.

PSI is PSI, shouldn't change just because you are running larger tires, especially at Load Range D, which means softer side walls than load range E.

Also, you should actually be able to run higher pressure with lager tires because there are more total sidewall rubber to compress than smaller tires.

Then again, people tend to get angry whenever I talk about science and facts.

So I'll stop.

Glad it works out for you though, and it look really good!

It’s actually opposite more tire area requires less psi to support the load ...it’s about pounds per square inch...larger tire = less psi

 

[Arterius2]

It’s actually opposite more tire area requires less psi to support the load ...it’s about pounds per square inch...larger tire = less psi

No, science doesn't work like that.

Yes, PSI = pounds per square inch, means it's measurement of the the force of the air pressure at any given point, regardless of the size of the tire.

Pressure is a constant parameter, it only varies when your total volume changes. If you have a larger tire, it means you have more total volume for the air to compress vs a smaller tire, thus larger tire at the same PSI will compress a longer distance than a smaller tire, while retaining the same PSI value as the smaller tire.

 

[Gotcha-Again-LOL]

No, science doesn't work like that.

Yes, PSI = pounds per square inch, means it's measurement of the the force of the air pressure at any given point, regardless of the size of the tire.

Pressure is a constant parameter, it only varies when your total volume changes. If you have a larger tire, it means you have more total volume for the air to compress vs a smaller tire, thus larger tire at the same PSI will compress a longer distance than a smaller tire, while retaining the same PSI value as the smaller tire.

But it bears more load without deforming because of the contact area...it’s about contact patch etc.

https://txtire.com/blog/view/jeep-tire-pressure-for-oversized-tires

 

[Buckster]

No, science doesn't work like that.

Yes, PSI = pounds per square inch, means it's measurement of the the force of the air pressure at any given point, regardless of the size of the tire.

Pressure is a constant parameter, it only varies when your total volume changes. If you have a larger tire, it means you have more total volume for the air to compress vs a smaller tire, thus larger tire at the same PSI will compress a longer distance than a smaller tire, while retaining the same PSI value as the smaller tire.

Hmmm, I guess nobody told the cycling tire industry about science. Mountain bikes run larger tires so they can run lower pressures, road bikes are trending to larger tires (lower pressure, more comfortable ride, minimal impact to rolling resistance). Well established across all offroad platforms that bigger tires run better with lower pressure. You run your whatevers at 40psi and I'll run my 37s at 30ish. Guaranteed I'll enjoy my ride more.
I'm not angry, I just think you have your facts misconstrued.

 

[Arterius2]

But it bears more load without deforming because of the contact area...it’s about contact patch etc.

https://txtire.com/blog/view/jeep-tire-pressure-for-oversized-tires

And I'm telling you that 27 PSI for your load range D is underinflated.
I have made extensive research and wrote several articles on this forum regarding proper tire inflation but I won't get into that.

The point I'm making is, in regards to ride quality.
This is why you see cars with smaller tires and thinner profiles, factory stock specs usually ask for lower PSI, while vehicles with larger tires with more sidewall, and in relative terms, that weighs more, actually require higher PSI to retain optimal ride quality.

For example:

28 PSI for a Ferarri 360
33 PSI for a Rav4
36 PSI for a Wrangler
38 PSI for a Raptor etc
65 PSI for a F350
100 PSI for a Semi

Of course you can drive an underinflated tires without too much issues, in fact, you'd probably call it "comfortable" because it's soft and bouncy. But at a cost of improper tire wear, rolling resistance, road noise and fuel mileage.

 

[Arterius2]

Hmmm, I guess nobody told the cycling tire industry about science. Mountain bikes run larger tires so they can run lower pressures, road bikes are trending to larger tires (lower pressure, more comfortable ride, minimal impact to rolling resistance). Well established across all offroad platforms that bigger tires run better with lower pressure. You run your whatevers at 40psi and I'll run my 37s at 30ish. Guaranteed I'll enjoy my ride more.
I'm not angry, I just think you have your facts misconstrued.

I'm not talking about off-road. Obviously I air down to whatever suitable for the obstacle I'm wheeling for. On-road performance is absolutely science-driven as well.

It's not just about how soft and bouncy your ride is.

And no, I don't run my tires at some random arbitrary pressure, like 40 you've claimed.

It's currently at 34 right now depending on temperature.

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