Airing down.

  • HTML tutorial

3wbdriver

Rank IV
Launch Member

Influencer II

1,298
Leesville, Louisiana
Member #

6620

I generally air down to 20 psi because that seems to be the popular pressure for most members of my club. I remember 12 was considered the minimum to keep the beads seated in the old bias ply days, but I honestly don't know what is considered a minimum on steel belted tires. I have been as low as 16 once or twice but I couldn't feel a difference over 20. So I just run 20 now.
 
  • Like
Reactions: Justin Cadiz

Renegade

Rank IV

Enthusiast III

1,212
Texas
20 or so.

I have done 8 in my jeep and not blown or spun a bead, but that is usually in soft sand, not rocks or other hard objects that could push against the sidewall.
 

BCBrian

Rank V
Launch Member

Advocate III

1,836
Boulder Creek, CA
Member #

3344

I normally air my DuraTracs down to 18PSI but may vary that as conditions demand. Weight load, surface and weather all play a part in choosing the appropriate pressure.
 

CalTexMex

Rank V
Launch Member

Pathfinder I

1,798
Fremont, Ca
Member #

5593

I run 315/75 r16 maxxis MT's on stock rims and I air down to 16. With the extra weight of aftermarket bumbers, winch and gear, I get enough sidewalk flex when I'm in the rocks. The prob I'm trying to avoid is peeling a tire off the rim when sliding sideways into a rut or running really off camber trails.
 

Neil Q Smith

Rank V
Launch Member

Member III

2,306
Sandnes, Norway
First Name
Neil
Last Name
Smith
Member #

6113

Usually air down to something in the order of ca.12 psi for "general air-down purposes".

However, as many of the thread articles above correctly state, it all depends on a number of factors.
(weight of vehicle, weather conditions, road conditions, age / dimension / tread depth & tread type / tire composition / type, degree of "ride softness" required, driver experience, etc.).

Driving in Norway an Iceland in winter, its good to reduce the air and gain a larger / softer footprint with each wheel.
Each occasion is unique, but a general air down to ca.12 PSI seems to work fine in most cases.

Driving over sharp lava in Iceland, we sometime go down to ca.8-10 PSI
Not had any issues with it to date :)

I have even seen air down to ca.2-5 PSI when driving on soft / slushy snow and glaciers.

I think common sense plays a key role in this decision.
If you have taken too much out, you can always refill (as long as you have compressor / air source)
Instinct and gut feeling also play a key role - if it doesn't feel quite right, adjust and try again.

And when the road conditions have improved / back to normal roads, re-inflate your tires ASAP.
Don't keep running on deflated tires on normal roads or at speed - it will significantly damage the tire and could cause potential accidents.

There are a lot of interesting and informative articles on the internet covering this subject,
but nothing beats the realtime experience.

Happy Driving !
 

Captain Josh

Rank V
Launch Member

Off-Road Ranger I

2,298
Mid-Michigan
First Name
Josh
Last Name
Fornwall
Member #

2398

Ham/GMRS Callsign
W4WOL
I run my KO2's at 15 psi in the sand (and fairly unloaded). 20psi for trails. On the street, I run a max of around 40, even though the tires can take 80.
 
  • Like
Reactions: Dave Decker

Overland California

Rank V
Launch Member

Influencer II

2,335
San Jose, California
Member #

11850

Safe air down PSI is really dependent on vehicle, vehicle load, tire Load Rating, wheel type/design, terrain type, and vehicle speed.

I typically air down to about 12 PSI in the big rocks and 18 PSI on the trails, deep snow and sand. Fire roads or snow/ice covered roads could be around 24 PSI to spread the tread block and keep things plush in the cab.
 

LandPirate

Rank V
Launch Member

Influencer II

1,977
Fort Collins, CO
Member #

3359

First thing I do when I hit a trailhead is air down. Comfort alone is worth the time for me and I don't know what's ahead. It can get nasty fast. Also, riding street pressures on washboard roads is tantamount to torture. All the other benefits, like puncture resistance and increased traction / capability you all already know.

I'm currently running very small stock sized tires, but airing them down allows me to travel comfortably off road, and I've taken my fully loaded Forester on roads I absolutely know I could not have done without airing down.

I can't wait to start running larger tires with more sidewall and a smaller wheel (from 16" to 15"). Currently running 215/65/16 Yokohama Geolandar G015 aired down to 16-18 PSI on sand and the trails, respectively. Fully loaded in back I run 20PSI rear on the trails.

IMG_3324.JPG
 
  • Like
Reactions: Daryl 32

trailspinTV

Rank VI
Launch Member

Influencer II

3,698
Peoria, IL
Member #

8207

Does airing down significantly affect clearance? I went for a bit of crawling/mud slinging last weekend with camping gear on board and was worried that airing down would lower my clearance at the axles and so I left them at 30-32 psi. The ride was definitely rough, but I was able to get over most obstacles. Is there a trade-off here?
 
  • Like
Reactions: Overland USA

Kelso

Rank IV
Launch Member

Influencer II

1,259
Cochrane, Alberta, Canada
Member #

6611

2500 suburban and I aired down to about 30psi on 3 tires, 20psi on one (strictly a strategic decision, I swear!). I probably could have gone down to 20psi all around but one thing to remember is when you air down at a trailhead your tires are likely hot. We camped overnight and the tires were down about 5 psi lower at freezing temps.

Needed the added rubber on the ground for the icy hills on the trail and it really helped.


Sent from my LG-H873 using Tapatalk
 

Cummins_Powered

Rank IV

Enthusiast III

I run 18psi on my JKUR. My 35x 12.5 Toyo's recommend 45psi min, but I usually keep them at 40 if I'm on pavement.
That on road psi is extremely high. I run my 35" BFG at around 30 psi on the street (12-15 on the trail). For on road pressures, check out the "chalk test". The ride will be so much smoother if you let even 5psi out of those Toyos, there is no need to run 40.
 
  • Like
Reactions: britz

Smileyshaun

Rank V
Launch Member

Member III

2,779
Happy Valley, OR, USA
First Name
Shaun
Last Name
Hoffman
Member #

4799

Tire construction has a lot to do with it to I run cooper st Maxx on my sequoia(e rated ) and have to get down around 15 psi to get them to squat , on my tahoe with mtrs (c load range ) they start to squat at 20 . You will have to experiment to see what works for your rig .
 

britz

Rank VI
Launch Member

Off-Road Ranger I

3,089
Musselshell, Idaho
Member #

5767

Ham/GMRS Callsign
K6YTI
That on road psi is extremely high. I run my 35" BFG at around 30 psi on the street (12-15 on the trail). For on road pressures, check out the "chalk test". The ride will be so much smoother if you let even 5psi out of those Toyos, there is no need to run 40.
I agree, my 2dr's Grabbers run at 32psi, and I like the ride of the lower psi. And that 45 psi is supposedly the low end. I'll have to bring chalk down to town, no pavement around here for a good hour.
 

phxdsrtrat

Rank V
Launch Member

Member III

2,362
Glendale, AZ
First Name
Curtiss
Last Name
S
Member #

8501

I air my Nitto Terra Grapplers down to 25 psi from the recommended 35 psi on the pavement. I know many people go lower and I wouldn't hesitate to go down to 20 psi but haven't had any issues at 25 psi thus far (and thus far is 30+ years of off roading in the AZ desert).

-Curtiss