Tire Pressure Question ?

[Alto]

What is the Lowest Tire Pressure that I could safely run my Tires at?

The reason I'm asking is that (This may sound weird but True). Over here in Saudi Arabia there is Sand Everywhere but the problem is that the sand is more less worth less. You can't use it to Build, can't use it for Buildings or for Roads. The Sand has been blowing around for so long that it is smooth. It makes great Beach Sand. When I walk around without shoes or sandles (most of the time) the sand is soft feels great.

Let me explain it this way. When you paint you Explorer you must first sand, then primer, then paint. Well the Sand here is so smooth that it can't bond to anything. All the buildings and houses around here or most of them have the sand imported. Or else the fall apart and Cracks everywhere. Some friends at another Compound had theres done like that about 3 years old cracks everywhere. There moving because they feel its going to collapse in on them.

Now that you understand why let me ask again. The sand is so soft that there is no grip. So I would like to air down as much as I can to get the biggest foot print possible.

My rims are stock 15"x7" Tear Drops. My tires are GoodYear AT/S 31"x10.5". Information would be help full.

 

[Jim F]

I believe anyone answering that question on this board would only be guessing. I would go to Goodyears website and locate their email address and send them the description and question. They are the experts and have resources to be able to help without damaging their tires and making you buy another brand when/if the tires fail.

Here's an email address I found on Goodyears site:

consumer_relations@goodyear.com

 

[Alto]

Tried !

I contacted Consumer Relations they more or less said... We can not advise you to air down bla bla bla $%@)*@$)*&@)*&@)*&#)*@&#)*@#&)*@@)#$*&@....

Anyhow what do people usually air down to? For sand?

I understand why. But they know that everyone Airs Down to play in the Rocks & Dirt & Sand...I guess they are just protecting themselves.

 

[Maniak]

It really depends on the tire construction, rim size and what the terain is like.. In Arizona sand, when wheeling on Sand/Rocks I run 15psi on 32x11.50 BFG At's on 8" rims

An article I read a while ago suggested you air down until you lose 1/3 the height. This will increase the contact patch more than 200%. The problem is that when you do that your sidewall are vulnerable(sp?) to getting cut and you cannot go fast. If you go too fast you can overheat your tire and blow them. If you are going too fast and turn you will roll the tire off the rim.
You can get beadlocks which bolt your tire to the rim to keep them from popping the bead at low pressures (but that is normally for very very low pressures for very very slow going)..

A slightly narrower rim will help you keep the tire on (e.g. an 8" rim would be better than a 10" rim for a 32" tire)..

Now according to my off-road book (written for overland trips) it says Not to run very low pressure in the Sahara since there are very sharp rocks that will kill a sidewall. It recomended to use larger (wider) tires and keep sand ladders handy.. Try to go in a straight line as much as possible.. and even had some tricks for driving on the dunes (I don't get to do that.. so I don't remember what it said.. but if you want I can dig the book out and give you more information about it)..

Oh yea.. I do remember it said to keep your center diff locked (already done on a 4x4 Explorer (not control trac)).. use 4hi.. not 4low.. and keep your momentum up..

Hope that helps..

 

[Robert]

You would have to let out some serious air to get down to drop 1/3 the height. I dropped my 265 75R16 tires down to 15 PSI from 35 PSI when I went through Box Canyon last March and only dropped 3/4". 15 PSI does seem about right for 32" tire though. It was the first time I ever aired down and I couldn't believe the difference it made in traction and comfort.

 

[Jim F]

So Robert are you going to run lower than 35psi normally now for more comfort?

 

[Robert]

No, I have been running my tires at the Ford recommended 30 PSI for the first four years. To see if it made any difference in mileage I bumped them up to 35 PSI several month ago. It didn't have any affect on my mileage. What I did discover though is that they are smoother and quieter at 35 PSI than they were at 30 PSI unless I go off-road. 35 PSI will rattle everything inside when going down dirt roads. Here in Arizona, the roads are for the most part in good shape. If I were back east I probably wouldn't like 35 PSI as much. When I go off-road I lower them. I found that when I was at 15 PSI I could drive over baseball sized rocks without hardly feeling them. Off road and on road require two different settings.

 

[SteveVB]

Alto,

Ive run many tires in the 12-15 range on sand. Some even lower, but remember you loose some clearance and end up pushing more sand. I have the Goodyear AT/S on my stock rims(7") and run them at 20 in the dirt, 12-15 on the beach, and 27-28 on the street.

Depending on how far and fast you have to drive 15psi or less would be fine on the sand. Like Maniak said the thing to watch for when you lower the pressure is the tire rolling off the rim if you put a big side load on the tire, such as turning or runnig along a hill, and overheating when your traveling fast.
Best thing to do would be to try a few pressures and see what you like. The lower pressure puts more sidewall on the sand giving you more flotation, so as low as you can go and still keep the tire on the rim would be ideal, so trial and error.

 

[Blue Steel]

an old trick for getting the tire back on the rim is to spray airisol lighter fluid in the tire and wheel and then get a can of wd40 and make it a flame thrower to light the fluid. make sure you're well away from the tire though, cause it goes "pop" jump up and reinflates the tire. better than trying to manually get in on the wheel.