what sand pressure

[Thelma]

Hi, We attempted our first serious go at sand driving . Byfield state forest, Stockyard Road. The last section as it goes up. The PS would not ! I dropped to 20 psi . Lowest I could go without a pump. What are you dropping the standard 18" tyres too for soft rutted sand, should I lock rear diff ?
Cheers for any advice

[geopaj]

I feel comfortable going to 16-18psi but, as you’ve alluded to, you need a compressor to reinflate.

On a few occasions, I’ve been down to 10psi but you need to use caution at this pressure - don’t drive fast and definitely don’t do any fast/sharp turns as there is a rust of rolling the tire off the rim.

You would be amazed the difference going from 20 to 16 psi makes... and again from 16 to 10psi.

[Pwoffey]

Of course it all depends on how soft, how deep, whether there are inclines, even time of day (temperature of the sand). First things first. If you are venturing onto soft sand then you will need to air down and then air up again when you get back onto the road. So a compressor (or at least a foot pump if you are energetic) is almost essential if no one else in the group has one, or there is no service station nearby. Next, turn off the ASC, because you don't want any unwelcome momentum-spoiling braking if the ASC senses a tyre losing traction. As far as pressures go, on soft sand, I would generally air down to no higher than 18 psi and am quite prepared to go down to 14 psi even from the get-go, depending on conditions. I start putting a little more thought when going lower than this, but I have been down to 10 psi on rare occasions. I sometimes engage my rear locker, but for me it's really all about tyre pressures (and trying to drive on someone else's tracks.) Also, I would never venture onto sand without a long handle shovel and some Maxtrax.

I have never been to Byfield, so others may be able to give more appropriate advice for that area.

[old Jack]

On 18 inch passenger construction tyres I am always wary to recommend going below 16 psi unless it is an emergency due to the low sidewall height and the soft sidewalls of a passenger construction tyre, you have a greater chance of sidewall damage.

On the Pajero Sport you should also consider fitting aftermarket intercooler and sump underbody guards, the factory guards are only slash guards and bend easily in soft deep sand. The result can be damage to intercooler and radiator, this is far more expensive than a set of aftermarket guards.

OJ.

[nj swb]

Looking at this from a slightly different perspective:

I don't know the particular track you were on, but I've driven sand on Fraser & Stradbroke, and multiple SA beaches / dune play fields / Simpson Desert crossings, and I have no reason to suspect that a Pajero Sport isn't a capable sand vehicle. So why did you have a less than awesome experience?

I'll presume you were on road tyres, because nothing here has suggested otherwise. In my experience, road tyres don't normally dig in sand, because they simply don't have enough "bite" to grab sand and throw it out. They simply slip on the top, and I (personally) don't believe pressure makes that much difference with road tyres on sand.

Most likely, if you didn't turn off ASC, that was detecting wheel spin on the sand and cutting power. We've all been caught out by that, and occasionally still get caught out. On sand, hit the ASC Off button.

If that didn't fix the problem, then definitely try the rear diff lock - but only for attempting "tricky bits". Again, in my experience on loose & rutted sand, locked diffs (centre, rear, front) make the vehicle follow ruts more aggressively, resulting in the vehicle being thrown side to side more than with everything unlocked. On sand, don't be afraid to use diff locks as you need them, but see how far you can get without them. Eventually you'll learn to recognise what you can drive without them, and what you'll need them for.

As others have stated, if all of the above hasn't worked, don't be afraid to drop your pressures lower - with all of the considerations that have been well covered above.

Don't have a compressor? Not the end of the world. You can cross the country quite safely on 10 psi - if you drive slow enough. If you get caught out with low tyre pressures and can't pump them up, drive slowly until you can. Go lower, drive slower.

[old Jack]

The Pajero Sport has an excellent traction control system so in most cases it will be better than the RDL as the RDL disables the TC system to the front axle.

ASC off selection catches many people out, even if you select it off, as soon as you turn the engine off the ASC will automatically come on when you restart the engine. However if you use low range then ASC will be automatically turned off.

The PS 8 speed is a great auto but in soft sand it is best to use the semi manual mode and low range as the torque convertor locks up from 3rd gear onwards, so ATF temps will be lower and you will not be losing drive by a slipping torque convertor. Using Drive will result in the auto selecting a gear too high and the torque convertor will unlock in gears 3rd and above, resulting in poor performance and the car will feel like it is struggling.

NJswb and I agree on most things, except tyre pressures on HT tyre's, lower tyre pressures will result in more floatation and less wheel spin. You will need less engine power to traverse the same section of sand if you have lower tyre pressures. When climbing even gently gradients then AT tyre's will get you further than HT tyre's, agressive AT and MT tyres will get you even further than HT's but as soon as you get any wheel spin the more agressive tyre's will dig down very quickly.

On 18" rims with HT's at 16 psi limit your speed to 40kph, your tyre will heat up very quickly when driven at higher speeds and lower pressures.

OJ.

[dragonjon]

how much tread do you see on a 2 wheel drive beach buggy ?
virtually zero
less tread the better on sand
personally i never go below 18psi never had a problem
Get those bash plates though

[old Jack]

In relation to footprint length and tyre pressures have a read of this thread and its links.

https://www2.pajeroclub.com.au/forum/showthread.php?t=30236

OJ.

[nj swb]

how much tread do you see on a 2 wheel drive beach buggy ?
virtually zero

A completely different situation. Beach buggies are typically smaller & lighter, with a much better power to weight ratio, with larger & wider tyres, and make great use of speed / momentum to get where they're going. A Pajero Sport is not a beach buggy.

If you google for tyres for beach buggies or sand rails you get lots of images like these:

less tread the better on sand

Let's agree to disagree.

[littleriver]

https://youtu.be/ki3FWdTjc90

[Thelma]

Thanks for the replies. There was some points I had not thought of. It's my first 4x4 auto finding my feet. Love the 8 speed.