Airing down tires with camper on

[Doff]

Wondering if people have any input or suggestions on what PSI to air down tires with a fully loaded FWC on the back? I would imagine it would be a higher PSI than if there wasnt a camper on the back

 

[Wandering Sagebrush]

Try this search on Google.

site: wanderthewest.com "airing down"

 

[JHanson]

In general, try about 20 to 25 percent lower than whatever your street pressure is for dirt tracks, 30 to 40 percent lower for four-wheel-drive trails, and up to 50 to 60 percent lower for very soft sand. So if 40psi is normal, try around 30 for dirt roads, 25 for four-wheel-drive tracks, and 20-18 for soft sand.

 

[Wallowa]

In general, try about 20 to 25 percent lower than whatever your street pressure is for dirt tracks, 30 to 40 percent lower for four-wheel-drive trails, and up to 50 to 60 percent lower for very soft sand. So if 40psi is normal, try around 30 for dirt roads, 25 for four-wheel-drive tracks, and 20-18 for soft sand.

I have a slightly different approach....only reduce tire pressure if you can't otherwise get traction..example, White Rim Trail...4X4 for sure but tons of rock; no pressure reduction [E Tires / 60 psi]....higher pressure helps prevention of sidewall and tread punctures...I do this on my dirt motorcycles and Tundra/Hawk...your mileage may vary! Hey, just my way.....

 

[JHanson]

I have a slightly different approach....only reduce tire pressure if you can't otherwise get traction..example, White Rim Trail...4X4 for sure but tons of rock; no pressure reduction [E Tires / 60 psi]....higher pressure helps prevention of sidewall and tread punctures...I do this on my dirt motorcycles and Tundra/Hawk...your mileage may vary! Hey, just my way.....

Of course you adjust for conditions, which was why I Italicized in general. But airing down isn't only about traction. It significantly increases ride comfort over rough roads and trails, and reduces stress on the suspension. It also, importantly, reduces wear and tear on the trail.

 

[ski3pin]

Try this search on Google.

site: wanderthewest.com "airing down"

A popular topic on Wander the West -

Stupid Question: Airing Down

Airing Down with a Camper

Airing Down Question

cold vs hot tire pressures when airing up or down

Tire pressure on dirt roads

Off Road Tire Pressure

 

[fuzzymarindave]

It may be useful to know your axle loads (from truck scale) and the tire manufacturer load tables for various psi. Here is a sample link for Toyo tires (which I happen to have).

https://www.toyotire...nflation-tables

 

[Wallowa]

Of course you adjust for conditions, which was why I Italicized in general. But airing down isn't only about traction. It significantly increases ride comfort over rough roads and trails, and reduces stress on the suspension. It also, importantly, reduces wear and tear on the trail.

Ride comfort and damage to roads...never thought about that....

 

[JHanson]

Ride comfort and damage to roads...never thought about that....

I once had to do trail survey work with a guy who refused to engage four wheel drive until his tires were spinning and digging up the substrate. Then he'd refuse to air down until, again, his tires were spinning and digging up the substrate. Better to be proactive.

 

[Wallowa]

I once had to do trail survey work with a guy who refused to engage four wheel drive until his tires were spinning and digging up the substrate. Then he'd refuse to air down until, again, his tires were spinning and digging up the substrate. Better to be proactive.


Hmmmm...Ok, I get that; no ripping up ground...but with respect...all off-roading "damages" substrate; unless of course it is on solid rock...we can pretend we are not degrading the route we travel, but we do, and minimizing that impact is always prudent...

Back to airing down...here it is primarily for travel across snow and less frequently through mud. Only time I should have but did not air down was between S. Coyote Buttes and White Pocket on the "short-cut" direct route; sand was so deep [deep existing ruts in sand] I buried my winch on the front of the Tundra...some anxious moments maintaining momentum...but I got through.

Back to OP's query, I checked the Cooper AT3 load vs psi chart for my size 10ply tires after putting my Tundra and fully loaded Hawk on a truck scale to measure total weight and weight per axle...my sweet spot was 60psi [all four tires], with a heavy diesel front may need more?...don't forget spare...after that as you are so inclined I would go with JH's recommendations on % to air down...if you feel the need.

 

[ramblinChet]

Personal safety trumps dirt every time.

On the trails I am in 2WD and it is nothing short of amazing where a skilled driver is capable of safely taking their vehicle with no damage to the trail. When I find myself in an area that can not be traversed in 2WD it now becomes time to take advantage of 4WD. The next step comes with I engage my front locking differential. The next and final step is taking advantage of a winch.

Mixed in between all of the steps above involves the use of MAXTRAX and other "road building" exercises. If I install a rock somewhere I put it back where I found it once I am through. I am certainly not one of those guys who just presses on the skinny pedal harder when I find myself in trouble - I am a huge proponent of the tread lightly principal.

But I tell everyone I meet there is absolutely no reason to be in 4WD unless it is absolutely required. You are doing yourself and others a disservice by not permitting your knowledge and skills to develop plus you have already eliminated one key safety step if you find yourself stuck in 4WD.

When I began off-roading in the early 90s it was in a Jeep with bald street tires and no lift or lockers. My best buddy was in a 2WD Chevy S-10 with similar limitations. There is something to be said about the knowledge and skill gained and associated with examining a potential obstacle and using your mind to move an object such as your truck through it in three dimensions while taking into account traction, suspension movement, etc.

 

[Vic Harder]

Back to OP's query, I checked the Cooper AT3 load vs psi chart for my size 10ply tires after putting my Tundra and fully loaded Hawk on a truck scale to measure total weight and weight per axle...my sweet spot was 60psi [all four tires], with a heavy diesel front may need more?...don't forget spare...after that as you are so inclined I would go with JH's recommendations on % to air down...if you feel the need.

Yep, with the diesel I end up running 60/55 psi F/R, fully loaded. On the washboard of Hole-in-the-rock road I aired down to 45/40. It helped, sort of...

 

[JHanson]

Personal safety trumps dirt every time.

On the trails I am in 2WD and it is nothing short of amazing where a skilled driver is capable of safely taking their vehicle with no damage to the trail. When I find myself in an area that can not be traversed in 2WD it now becomes time to take advantage of 4WD. The next step comes with I engage my front locking differential. The next and final step is taking advantage of a winch.

Mixed in between all of the steps above involves the use of MAXTRAX and other "road building" exercises. If I install a rock somewhere I put it back where I found it once I am through. I am certainly not one of those guys who just presses on the skinny pedal harder when I find myself in trouble - I am a huge proponent of the tread lightly principal.

But I tell everyone I meet there is absolutely no reason to be in 4WD unless it is absolutely required. You are doing yourself and others a disservice by not permitting your knowledge and skills to develop plus you have already eliminated one key safety step if you find yourself stuck in 4WD.

When I began off-roading in the early 90s it was in a Jeep with bald street tires and no lift or lockers. My best buddy was in a 2WD Chevy S-10 with similar limitations. There is something to be said about the knowledge and skill gained and associated with examining a potential obstacle and using your mind to move an object such as your truck through it in three dimensions while taking into account traction, suspension movement, etc.

Chet, I think you are contradicting yourself here. You say personal safety trumps dirt, yet engaging four-wheel drive on a dirt road, even if it's not "absolutely required," increases safety. I understand the value of experience gained with bad tires, etc.—been there—but it's incontrovertible that having traction at all four corners is better—that is, safer—on a loose surface.

 

[Wallowa]

Yep, with the diesel I end up running 60/55 psi F/R, fully loaded. On the washboard of Hole-in-the-rock road I aired down to 45/40. It helped, sort of...

Oh yes, the famous King of Washboards on the HTR road...we solved that by accelerating to 55mph+ and skimming the tops of the waves...until we had to chatter down the speed to make the corners! What 45 miles of the HTR? Worth it, great hideaway camping spots and hikes out there....

Ps...So many of us old guys grew up in the bush with old beater PUs that were 2 wheel drive ['36 Ford PU with mechanical brakes] that we learned to drive off road and judge the conditions without the benefit of 4x4, like loading rocks into bed to gain traction...unfortunately many today believe that with 4x4 nothing can really stop them or mire them in....kinda like the folks that die following the GPS.. No substitute for experience and good judgement.

 

[JaSAn]

2012 Ram 2500 4X4 & Grandby, Cooper Discoverer AT3, 245/70-17s. Truck and camper at 7900 lbs balanced front and back.
70 psi paved roads.
40 psi on gravel, dirt, etc. @ 30 mph max.
Only been on soft sand a few times at 40 psi; worked ok.

 

[ramblinChet]

Chet, I think you are contradicting yourself here. You say personal safety trumps dirt, yet engaging four-wheel drive on a dirt road, even if it's not "absolutely required," increases safety. I understand the value of experience gained with bad tires, etc.—been there—but it's incontrovertible that having traction at all four corners is better—that is, safer—on a loose surface.

Well, I guess this is just another one of those topics where we will agree to disagree and that's perfectly fine. Different things work for different people. I just tend to go a bit deeper regarding safety issues.

I was raised in the Great Lakes in a small town on the shore that is usually second in the nation for annual snowfall. Most of the folks up there with 4x4 trucks that I knew never really used it - we just learned to drive in with poor traction all the time. Of course we had 4x4 vehicles but there was something to be said regarding being in touch with the environment and understanding how much traction you had or did not have at any given time. Being in 2WD forces your to concentrate and drive the vehicle and not do stupid things just because you have the false perception of adequate traction.

See, many people fail to realize that just because you can accelerate better in 4WD that usually provides you with an inflated perception of how much braking or steering ability you have. Driving in 2WD in conditions with poor traction is a constant reminder that you don't have great steering or stopping ability also. The same holds true on wet roads, muddy trails, gravel, etc.

And from a safety perspective steering and stopping trump the ability to accelerate virtually every time.

For example, attempting to drive up a moderately steep trail with a mixture of moist dirt, some small rock obstacles and the occasional tree root. If you can make it up with few problems in 2WD you can be nearly certain that coming back down can be done safely. If you are forced to use 4WD now you must begin to question how much stopping and steering ability you have on similar climbs or descents. If you were just in 4WD the entire time and made it up with no real troubles now you are partially blind to the available traction or lack thereof.

Again, I stand by my earlier statement that driving in 2WD is safer in areas with and without poor traction since it forces the driver to maintain an acute awareness of the surroundings and available traction. That is the epitome of safe driving.

 

[craig333]

I'm with Jonathan on this one.

 

[rubberlegs]

To increase comfort and reduce shaking the camper to bits, we reduce from 45/62 psi down as low as 15/20. Washboard isn’t as bad as big rocks, so we reduce to about 25/30. Were not rock crawlers but enjoy getting to places on pretty rough roads.

 

[JHanson]

That's okay, Chet; we can disagree and I do, amiably.

However, to your statement:

"Again, I stand by my earlier statement that driving in 2WD is safer in areas with and without poor traction since it forces the driver to maintain an acute awareness of the surroundings and available traction. That is the epitome of safe driving."

. . . I would say, Okay, perhaps it's better to drive in traffic without a seat belt, since it forces the driver to maintain an acute awareness of what other drivers are doing . . .

 

[ramblinChet]

Let's remain on topic and debate one safety issue at a time - we can come back to seat belts after we conclude this discussion.

My argument is that driving in 2WD provides more available information to the driver regarding available traction when compared to driving in 4WD. This additional information is helpful in the short term since it immediately provides the driver with an accurate measure of traction where this vehicle is at the present moment. This additional information is also helpful in the long term since it directly enhances driver skill.

Your counter argument is that reducing the available information regarding traction to the driver is safer in the short and long term. And that's exactly what driving in 4WD when it is not necessary does - it reduces the level of detail regarding available traction to the driver. Is this your argument?