what PSI do you run on trails?

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Knight Raider

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Off-roading I’m at 15 to 12psi on the pavement I’m at 28psi. I have a Jeep JKU with 35” tires on stock rims. I’ve not had any problems. I ran the same on my old 2 door Jeep jk with 33” tires.
 
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I always drop to 18 psi when I hit the dirt.

First and foremost, reducing the tire pressure down from road pressures makes a huge difference regarding traction. It also makes the truck ride much nicer on washboard/rough roads.

Smaller diameter wheels with high profile tires work best. Large diameter wheels and low profile tires are best kept on the pavement.
Many years ago, before i got educated, and started thinking about it, I just ran street/Hwy pressures everywhere. This was before portable air compressors became relatively available or cheap. Had to run a wash board dirt road that was rock hard for 2 hours, when we got disorientated in the middle of the night in BFE (Central NV). Finally realized that we were on the wrong side of a mountain when the moon finally peaked itself over the horizon. Chalk it up to taking the wrong fork in the road, and not being familiar with the area (pre-GPS).

Anyway, airing down would have been a gamble since the nearest town/place that might have a air hose was SOMEWHERE, real far away. Had the same size tires then as now. The only difference being a D vs E rating. From what I now understand, my E rated 285x75x16 tire on my 2500 HD, might have to go a little lower that a 18 psi volume to see enough 'squish' to have the benefit someone with a less stout C or D tire might get. I know that it would have minimized the teeth rattling I endured that night. I do know it loosened all the plastic hubcap nuts on the OEM wheels that night. Luckily I didn't lose any of them.

With the portable Vivair 88P, I can now safely and confidently lower my trucks pressures to a level that is better suited to the conditions I might encounter. And when back on hardtop, air back up to a appropriate pressure that wont damage my tires.
 
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Truckee

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Your definition of high varies from rig to rig and tire to tire on the highway a higher pressure equates to better gas mileage due to reduced resistance or friction. Offroad its totally different, if i were to go by my door jamb sticker id be way off since im 2 tire sizes larger than stock and the tires are e rated all the way up to 80 psi max unlike p rated 45psi so in the grand scheme of things the pressures i listed that i run are rather low. Also i have mud tires so no real need to air down much unless i start to get stuck. 20psi for me is like 5 psi for you
I think your highway tire pressure is too high. You went from the recommended, 35 psi for a P-Metric tire all the way up to 60 psi to compensate for an LT, E load tire?

If you asked The Tire and Rim Association (TRA), it would go something like this:

P265/70R17 @ 35psi = Load Rating 2392 lbs.

P-Metric to LT tire conversion.... derate 2392 by 10% = 2152 lbs

Take the Load Inflation Table for the BFG KM3 and you should be around 36psi, front and rear.

Screen Shot 2019-11-22 at 9.56.00 AM.png

If you are much heavier than stock, towing, etc, I can see going up to 40 psi... maybe even a little higher but not 60 psi. I understand most people want to maximize fuel mileage but over-inflation also reduces your tire's contact patch, reducing braking/cornering ability.


It depends on what im driving on.
33" e rated to 80psi mud tires on 17"rims:
Highway driving/ normal 60 psi
NF roads between 60 and 55 psi
Mud between 60 and 45 psi
Rocks between 50 and 35psi
Sand 30 psi to as low as 20
Ive left them at 60 and have had problem on any of these terrains just a rougher ride.
 

Boostpowered

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I think your highway tire pressure is too high. You went from the recommended, 35 psi for a P-Metric tire all the way up to 60 psi to compensate for an LT, E load tire?

If you asked The Tire and Rim Association (TRA), it would go something like this:

P265/70R17 @ 35psi = Load Rating 2392 lbs.

P-Metric to LT tire conversion.... derate 2392 by 10% = 2152 lbs

Take the Load Inflation Table for the BFG KM3 and you should be around 36psi, front and rear.

View attachment 128099

If you are much heavier than stock, towing, etc, I can see going up to 40 psi... maybe even a little higher but not 60 psi. I understand most people want to maximize fuel mileage but over-inflation also reduces your tire's contact patch, reducing braking/cornering ability.
According to the little chart you provided im right under target psi for the weight of my truck 3200lb front 3100lb rear. Ill take some pictures maybe saturday that show you what the different psi looks like on my tires. However i dont have bfg tires
 

Truckee

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The chart is "Per tire." 60 psi would be 3050 lbs x 4 = 12,200 lbs. There's some manufacturer's fudge/safety factor in there as even the 2,152 lb x 4 = 8,604 lbs.... which is much more than your GVWR.
 

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I plan on doing some offroading in Oklahoma this weekend on some 4x4 required back roads., I'll take them down to 35psi, that's after driving 3 hours to get to the trail head so I guess that's more like 32psi maybe 30psi cold.
 

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I run 26psi year round. In my country I've never needed to ait down. Bc Interior Mountains are pretty solid ground and I've never needed to scramble over rocks. Even our beaches tend to be pretty solid or have choices to avoid the really soft sand.
 

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I plan on doing some off-roading in Oklahoma this weekend on some 4x4 required back roads., I'll take them down to 35psi, that's after driving 3 hours to get to the trail head so I guess that's more like 32psi maybe 30psi cold.
That PSI might be okay for non ice under snow conditions. If it's over 3-4, you might consider 20 PSI if traction starts being a issue. If you have a compressor, than everything should be okay, as you can adjust as needed. If you don't, than the 30 PSI is probably as low as you want to go, unless you have access to a air pump station, to avoid possible tire issues on the hwy and tarmac.

There is a thread on OB, about compressors, what kind people have, and how they perform. Have fun, be safe, and enjoy :sunglasses: