Nitto Ridge Grappler 37" Recommended Tire Pressure

TakHardRock

New member
Hi everyone, I just got my new Nitto Ridge Grappler 37x12.5x17. I'm currently running 34psi cold right now, Nitto told me to run 25psi for daily driving. What's everyone running? Thank you!
 

cozdude

Guy with a Red 2-Door
I run mine at 28 as well but do the chalk test as Ddays mentioned. Will get you the best results for the weight of your jeep
 
All of the chalk test procedures I found said to start at the tire's rated max pressure stated on the side of the tire. Then go down in 3 PSI increments. The max pressure is something like 80 PSI! So maybe in an hour or two of decreasing pressure and driving forward and backward, the pressure should be in the ballpark of where it should be. Seems crazy to me.
 

OverlanderJK

Resident Smartass
All of the chalk test procedures I found said to start at the tire's rated max pressure stated on the side of the tire. Then go down in 3 PSI increments. The max pressure is something like 80 PSI! So maybe in an hour or two of decreasing pressure and driving forward and backward, the pressure should be in the ballpark of where it should be. Seems crazy to me.
Maybe don’t listen to random terrible information on other sites.
 

WJCO

Meme King
All of the chalk test procedures I found said to start at the tire's rated max pressure stated on the side of the tire. Then go down in 3 PSI increments. The max pressure is something like 80 PSI! So maybe in an hour or two of decreasing pressure and driving forward and backward, the pressure should be in the ballpark of where it should be. Seems crazy to me.
That's the stupidest shit I've ever heard. Was that from a White House press release?
 
That's the stupidest shit I've ever heard. Was that from a White House press release?
Maybe by the Secretary of Transportation.

I just looked at the top 5 in a web search.

If my tires are bigger and stiffer than factory, it seems that there should already be some crown at Jeep's recommended inflation level (37 PSI for my 2-door).
 

JamesWyatt

Caught the Bug
What those guys said ^^^
I typically run mine at about 28
It’s surprising how much better these vehicles handle when the tire is allowed to be in contact the road.

I was an idiot running my 315 E-rated KO2s on my JTM at 38psi for a time, wondering why I was nearly getting blown off the interstate by crosswinds. I mistook twitchy steering for better steering. I had tried going down to 33-ish, but I never thought to go lower. Then finally had a lightbulb moment after doing more research, and I tried going down further until at 28 it became a completely different vehicle.
 

Steve Williams

Caught the Bug
I found it’s of course very weight dependent. With my doors and top off I like 25psi on my Nittos for the pavement. How much air to run on the trail is a whole other discussion And changes with location and type of rock.
 
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