Off Road Tire Pressure - How Low Do You Go?

[TravelAmateurs]

06 Tundra DC w/ Hawk on full time
Cooper AT/3 E rated 265/70R17

Driving across the U.S. 45F/47R felt a little too hard on washboard & forest roads...good on highway.
For us 40F/42R was a good compromise for highway & back roads.
Soft Sand we dropped to 35 all around...worked well.

Using VIAIR 300P to air back up.

 

[ntsqd]

You quoted my post where I specifically talk about low speed and then give a high speed example. Would you like some apples with your oranges? Yes, obviously, if you're on terrain that allows you to travel 100 mph you aren't driving in the conditions I'm asking about.

You haven't been to an off road race. Yes, they are always trying to go fast, but they aren't always going 100 mph - particularly the slower cars like the Class 11's (Stock VW Beetles). Fast to them is the range of speeds you're talking about.

And thank for making my point, it is all apples and oranges. There is no single tire pressure rule that always applies. Saying high pressure cuts sidewalls may or may not be correct. It can't be stated as an absolute as you did. To repeat myself, the ideal tire pressure depends on the situation and the driver.

 

[Ace!]

Never been to an off road race? I've competed in off road races as well as non-timed off road events. I've been an active member of a 4-wheel drive club, traveled extensively off road and been a member of a team that was trained in off road driving/riding techniques.

You and I have said the same thing, that pressures should be adjusted to conditions. But I can tell it's important to you to feel like a winner, so you win, I lose. I hope that makes you feel better.

 

[Captm]

Wow, who knew that a tire pressure topic would create heat. This reads like something from "Expo" .
I air down when the pavement ends, back up when the pavement begins and adjust as necessary as we go. Basically using it as a seat of the pants suspension tool for fine adjustment when running on hard pack dirt, gravel and most importantly on washboards. Adjusting as we go for rocky terrain, sand, mud and one day soon snow. In my avatar I have the tires at 25psi, the front passenger tire looks like a balloon while the driver side is formed around the rock.
Cheers

 

[JHanson]

Jonathan, are you using the pump plumbed to your air locker for air up?

In the Tacoma, yes—it's the ARB Heavy Duty version, one step up from their basic but below the twin-cylinder version. It's decently fast. The twin-cylinder is noticeably quicker.

In my FJ40 I carry an Extreme Outback Extreme Air Magnum, which is really quick.

 

[JHanson]

Boys, boys.

Of course there are many variables that influence one's choice of tire pressure. Example: A few years ago on a trip in Egypt with three Land Cruisers, we needed to ascend the Dakhla Escarpment, a 1,000-meter-tall ramp of sand that spills off a cliff north of Mut—seen in the background here:

So we aired down:

However, that massive sand ramp is studded with vicious pieces of limestone called kharafish:

So to avoid sidewall slices (as much as possible), we couldn't go down as far as I would have liked. Fourteen psi would have done wonders for the flotation of our 235/85 16 BFGs, but we kept them at 25. That just barely got us up the escarpment, but we also had only one sidewall tear:

There's a short video of one section here.

So unless you're driving in pure sand, airing down is almost always a balancing act. But it is almost always a good thing to do for the vehicle, the trail, and your comfort.

 

[BillM]

I've gone as low as 20 psi in deep fine sand in AZ. At 25 psi we were stuck, dropping to 20 we drove out no problem and then aired up. I usually run 40-45 psi on pavement.

 

[smlobx]

Outer Banks is indeed a very unique environment!

Have you guys made a decision on a camper?

Not to take this topic off-road so to speak but yes we have!

We just put a deposit down for a Hallmark Everest that should be ready by April or so. Looking forward to enjoying some backroad adventures.
Thanks for showing us your fine rig!

 

[Ace!]

60 lbs here:

 

[craig333]

Its not just me either. The dog sure appreciates it when I air down

 

[Advmoto18]

After Jonathan's comments regarding air up times, I decided to save some time. I just ordered the ARB On-Board High Performance 12 Volt Air Compressor (CKMA12).

This winter's project...removing the rear seat in my crew cab and installing a dog platform/bed in its place. I plan on hard mounting the compressor under the platform deck. With an opening facing the door to dissipate heat.

 

[ntsqd]

It's not about "winning", it's about not letting what I consider to be a misleading statement to stand unchallenged.

I was able to stash that "made in chino" compressor and it's condensor under the bed, outboard of the frame rail on the driver's side.

 

[Advmoto18]

Too much rain and mud in the southeast for that setup. It would be caked in mud after one outing and corroded after a year.

I suspect you need to safety wire on those bolts if you're driving 90 - 100 mph off tarmac! And I'm not challenging your comment! I wish I could spin wire that well!

Personally, I drive much, much slower to savior the scenery because I don't know if I will ever get back again.

And road conditions and composition dictate to what extent I air down. With a wife, 2 dogs and a camper full of stuff, I air down to improve the ride quality and not break stuff.

But each to his own. At least your dust cloud will dissipate very quickly when you blow by me doin' 100 mph in your '91!

 

[smlobx]

After Jonathan's comments regarding air up times, I decided to save some time. I just ordered the ARB On-Board High Performance 12 Volt Air Compressor (CKMA12).

This winter's project...removing the rear seat in my crew cab and installing a dog platform/bed in its place. I plan on hard mounting the compressor under the platform deck. With an opening facing the door to dissipate heat.

Please consider taking pictures and documenting the project.
It is something that's on my radar as well.

 

[ntsqd]

The whole bracket clamps on (couldn't drill, fuel tank up tight on other side) so even a little loose would be a disaster. The safety wire is just for my piece of mind. HF sells the pliers, they're really not hard to use and they are great for field repairs! I keep a set in the traveling tool bag along with some wire. I debated that location for the reasons listed, but so far experience hasn't proven it to be correct. Though we don't travel in the SE, so there's that.

Most of the time off pavement I'm down to ~40 psi and travel between 40 and 50 mph unless it's really rough. It's one thing to go slow enough to enjoy the scenery. It's quite another to plod down a rough road and not have the scenery change for hours.
The 80 in the CTD was because of a broken rig 500 miles from home and the only U-Haul with a trailer to put it on was 150 miles away, at 3:15pm on a Friday (plug for the independent on the west side of Fallon, NV). The nearly 100 in the '91 Sub was crewing a broken desert racer with the hope of getting him fixed & back in the race.

 

[brianjwilson]

After Jonathan's comments regarding air up times, I decided to save some time. I just ordered the ARB On-Board High Performance 12 Volt Air Compressor (CKMA12).

This winter's project...removing the rear seat in my crew cab and installing a dog platform/bed in its place. I plan on hard mounting the compressor under the platform deck. With an opening facing the door to dissipate heat.

I like my ckma12. I had one on my Jeep, and have one in my Tacoma running lockers and airing up tires. Both mounted under the hood. I leave the hood open while airing up and haven't had any issue with them. It does sit in an area with higher than ambient temps, but there is airflow under the hood with the engine running and I'm driving away right after. The nice thing is the compressor stays relatively dry and clean, isn't obnoxious in the cab and it is tucked into an otherwise unused space. I almost bought the twin version but figured the extra speed wasn't worth having to mount it under the bed, exposed to the elements.

Obviously not plumbed and wired when I took the photo.


And wired everything through Toyota style switches for a factory look.


Previously I've used the MV-50 for years without problems, finally gave it to a friend. Then a few more years using a q89 (I think) which is a similar pump with dual compressors. Both were inexpensive and worked fine, but the ARB seems better suited to a permanent install, come with standard fittings and hardware.

 

[Advmoto18]

Very nice install BJW!

This unit will be simply for airing tires. I will have the space under the dog platform so I can avoid installing under the hood.

I've tried inexpensive (<$100) portable/handheld units and they were mostly disappointing. Why I ended up using the very small Best Rest cycle pump. While not designed for airing up truck tires, it works quite well albeit, whilst eating a meal.

 

[JHanson]

I documented the installation of an ARB rear locker on our Tacoma, including the compressor, here and here.

The second part is a video. If you click on the Vimeo link you'll get it in HD.

 

[TravelAmateurs]

06 Tundra DC w/ Hawk on full time
Cooper AT/3 E rated 265/70R17

Driving across the U.S. 45F/47R felt a little too hard on washboard & forest roads...good on highway.
For us 40F/42R was a good compromise for highway & back roads.
Soft Sand we dropped to 35 all around...worked well.

Using VIAIR 300P to air back up.

FWIW I'm airing up a bit after doing some reading on E rated tires. Seems like I've been putting a bit too much strain on the side walls for standard driving. 47F/53R for now but will still air down based on the situation...guessing I'll drop back to low 40's for parts of baja next week.

 

[BobD]

I like my ckma12. I had one on my Jeep, and have one in my Tacoma running lockers and airing up tires. Both mounted under the hood. I leave the hood open while airing up and haven't had any issue with them. It does sit in an area with higher than ambient temps, but there is airflow under the hood with the engine running and I'm driving away right after. The nice thing is the compressor stays relatively dry and clean, isn't obnoxious in the cab and it is tucked into an otherwise unused space. I almost bought the twin version but figured the extra speed wasn't worth having to mount it under the bed, exposed to the elements.

Obviously not plumbed and wired when I took the photo.


And wired everything through Toyota style switches for a factory look.


Previously I've used the MV-50 for years without problems, finally gave it to a friend. Then a few more years using a q89 (I think) which is a similar pump with dual compressors. Both were inexpensive and worked fine, but the ARB seems better suited to a permanent install, come with standard fittings and hardware.

Nice install. Are your switches from Air On Board?