Why to deflate while driving on sand?

[Duck Commander]

Most modern 4x4 vehicles have tires optimized for highway travel. The are as narrow as possible to reduce noise and friction for improved fuel economy.

Narrow tires make cars sink deep in soft surfaces like snow and sand. When sunken in, the front tires have constantly a small berm of sand in front of them. While driving they push this berm without ever being able to climb it. That produces a lot of extra resistance. More resistance requires more torque to keep the vehicle moving. But traction is not good on sand. The sand particles are not stable and tires tend to dig in deep - only creating more resistance. You'll be stuck in no time.

By airing down your tires, their footprint increases and they don't sink in as deep. That translates to less resistance and a lesser chance to dig in. Translates to a lesser chance to get stuck.

How much should you air down?
A a standard rule - about 2/3 down from your recommended highway pressure. So, if around 30 psi is your highway pressure, the psi setting for sand should be 10 psi.

If you drive in soft sand a lot, taller wider tires are a good investment. They have a much higher volume of air and can be aired down more easily to very low psi.
Tires with an aspect ratio of 50 or lower (like a 255/50 R 16) have very low volume of air and should neither be aired down much, nor be used at the beach in soft sand.:028:
By the way, don't listen to guys telling you that MT tires are bad for sand. Its not the tire design but the low tire pressure that is important - and your gentle foot on the gas, of course.

Here is another very valuable tip for driving in soft sand: Drive as straight as possible! Driving straight makes the rear tires follow in the same already compacted channel the front tires have created. By initiating a turn, the rear tires leave the channel and each of them will now create their own channel and thus will have to fight a small berm of sand each. That increases the resistance by 100%. Increasing the chance to get stuck. The tighter the turn the higher the resistance.

See attached photos showing BFG tires with full and low air pressure and the other two photos showing straight line and curved driving photos.

Soft Sand


Soft Sand Sink


Straight Line


Turned Line

[Wasif Ahmed]

You know Shafiq.....actually in desert driving I have seen people using tires narrower tires and haveing more fun as your car has that much more power to offer you.

Ideally in sand a 255/75 tire is better than say a 285/75

[alshamsi_m]

Hello Shafiq

Many people think that the bigger is the tier .. The better is your drive in the desert ... Actuelly. The secret is in the space between the tier and the car's body .. When the tier route in the sand it makes a sand sayclon and pushes the sand to the back ... The space is important because as their a space the tier can keep going freely otherwise it will jam and stop routing

The tiers' shops will try to fool you ... To make more sales and will never give you this TIP !!

[Duck Commander]

Ya wasif you are right to some extent, because of the huge tires weight the engine is struggling to move them, but recently I was in LIWA with my friend who is having 33 inch M/T tires. We were keeping 5 psi air in the tires and the car was floating amazingly. Even at few occasions we thought that may be we are having pop out because of the humps and sliding from the dunes, but no pop out. Ya due to humps the air pressure was decreasing and only once we refill to 5 psi.
Now if we were having narrow tires we would have more than 10 pop outs in that terrain even with 14 psi pressure.

[Indy]

Ya wasif you are right to some extent, because of the huge tires weight the engine is struggling to move them, but recently I was in LIWA with my friend who is having 33 inch M/T tires. We were keeping 5 psi air in the tires and the car was floating amazingly. Even at few occasions we thought that may be we are having pop out because of the humps and sliding from the dunes, but no pop out. Ya due to humps the air pressure was decreasing and only once we refill to 5 psi.
Now if we were having narrow tires we would have more than 10 pop outs in that terrain even with 14 psi pressure.

.. this is really interesting, thanks for the info, Shafiq

[caprihorse]

Yes, Shafiq, good point, you reminded me on one aspect.

When you are driving with low pressure, the tyre tends to slip diagonally on the rim. These causes to enter sand inside thre tyre, which results in more unbalanced weight on the wheel and sooner or later air leak and pop out. :035:

To test, if this really occurs at your car, before the trip mark the place with some marks on your rim and tyre. After the trip check if the markings are still aligned same as at the beginning. If not, your pressure is too low.

Generally aloy rims are higher production quality and more symetric as standard steel rims and tyres sit better. Air leak at steel rims is common at low pressure. When you are investing into new tyres, spare some money also on good aloy rims too. At the first stage of enhancing your brand new 4x4 toy, the proper rims and tyres are more important as suspension lifting and computer chip tuning. You can have wonderful torque after tuning, but as you step on the gas and your car flies away without tyres, you'll loose your enthusiasm and you may think 'What to do now...' :011:

[ahmedjamal]

Hello Shafiq

Many people think that the bigger is the tier .. The better is your drive in the desert ... Actuelly. The secret is in the space between the tier and the car's body .. When the tier route in the sand it makes a sand sayclon and pushes the sand to the back ... The space is important because as their a space the tier can keep going freely otherwise it will jam and stop routing

The tiers' shops will try to fool you ... To make more sales and will never give you this TIP !!

you mean the space between (idont no what they call 'em) points within the tire itself

[Wasif Ahmed]

Ya wasif you are right to some extent, because of the huge tires weight the engine is struggling to move them, but recently I was in LIWA with my friend who is having 33 inch M/T tires. We were keeping 5 psi air in the tires and the car was floating amazingly. Even at few occasions we thought that may be we are having pop out because of the humps and sliding from the dunes, but no pop out. Ya due to humps the air pressure was decreasing and only once we refill to 5 psi.
Now if we were having narrow tires we would have more than 10 pop outs in that terrain even with 14 psi pressure.

Believe me with narrow tires and 10 PSI you would go places you never reamed possible on 33 inch tires with 5 PSI. And there is no tire youc an run at 5 PSI without beadlocks you would have popped it for sure. Min pressure to keep the tire on the bead is 6 PSI Your friends tire gauge must be faulty ...LOL

[Duck Commander]

hehehe. may be wasif bhai but the amazing thing was even some time there was no or very less air in the tires as the car following us warned us and we refill but still no pop out,lolz.

Wasif what you think about 275 tires on my original fj wheels? Is it oki to change only the tires without changing the wheels?

[Wasif Ahmed]

hehehe. may be wasif bhai but the amazing thing was even some time there was no or very less air in the tires as the car following us warned us and we refill but still no pop out,lolz.

Wasif what you think about 275 tires on my original fj wheels? Is it oki to change only the tires without changing the wheels?

275's will work fien on your original rims...there is no need to change rims if you are upsizing your tires within reason