Driving on sand: Open diff, Traction Control, LSD, Locker, AT or MT

Ive only driven on sand a fue times, and it was by no means easy and im only on about the local beaches, soon learning that slow speed in Lo range is not that effective.

Ive seen that a fue ppl on here have photo's of driving in/thru desert and dunes, whats the best way to tackle sand, what traction aids are valued most when on the dunes, and what tyres does the majority use. AT's, MT's, thin or wide tyres?


Jas

Like most things there is no one simple single answer.

Sand varies an a lot from dry non compacted sand, to wet compacted sand, to pie crusted sand. Flat sand or dunes?

On compacted sand, high box and high speeds can be easily obtained.

Tyres? Well you can get specialised sand tyres but only in limited size range.

A/T are probably better then M/T as they are less aggressive especially if you have a heavy right foot.

Tyres are a compromise, we run on BFG M/T in our 110's This is a good all round tyre.

Lower the pressure when you need to and don't get heavy with right foot. Get a decent compressor to reinflate the tyres.

Dunes you need enough momentum to just get to top of dune but not over it, as you need to spy out the next part of the route.

HTH


Brendan

Sand is a unique surface which requires considerable power and speed which contradicts normal off road driving rules, forget sand tyres as these are specialised tyres purely for sand. The best option is stick with all terrains and air them down a little as you need as wide a tyre as possible, then as wide a footprint as you can get.

With sand you need four high as you need speed, to build this up you need to accelerate gently but consistently until you build up a reasonable speed, to slow and you will often sink, to drive effectively you will need the engine at its maximum torque for a diesel, or maximum power for a petrol, and maintain these engine revs. With an automatic you will need to hold whichever gear is best and prevent it changing up a gear.

One trick i use is to carry a couple of lengths of carpet, lay them out before you stop and sink, and drive onto them as they will give traction to pull off again.

LSD??? depends on the sand, generally i would say no, but if you have a centre differential then lock this, if you lock an axle diff and turn it often digs a wheel into the sand.

Momentum is key on sand, and when dune climbing you really need to climb them in a straight line at 90 degrees to the dune and not across them, if you drive across them it transfers weight to the lower side of the vehicle and it sinks quicker in most sands, inevitably the vehicle rolls and is damaged or trashed.

If you get stuck climbing you simple reverse straight down without risking your vehicle.

Wise words, and I'll just add a couple of things (in no particular order).
Unless you spend your life in the sand don't fit sand tyres as they are crap and dangerous on the road, not only when it is wet but even a slight dew.
The more aggressive the tyre tread the worse it usually is on sand. Low profile tyres are crap also as they don't increase the footprint enough when let down.
Park on a hard bit or use the example of the carpet - good idea. Park facing downhill if you can.
When you come initially to a stop try not to brake to stop, just roll to a stop. This stops a build up of sand in front of the tyre for when you want to set off.
Avoid cornering sharply, take large sweeps if you can.
I've often had my tyre pressure down to 1 bar to get out of trouble - but treat the tyres carefully and no high speed or rough cornering.
I spend more time in high range than low range.
Dunes are usually shaped with a steep side and a less steep side - make sure you don't fly over the top and...........!
Keep high when in dunes.
Never really needed my diff lock.
As soon as you feel yourself getting stuck, stop and let tyres down further or dig out/use sand mats. If you carry on you'll only make it worse. Many times I've just taken 5 minutes to get going again compared to someone who has really dug themselves in by sheer irritation and flogging a dead horse.
Tyres and pressures are the key - I'll stick my neck out and say I can beat any 4x4 running on road pressure tyres in soft sand with any other 4x4 running on the pressure I want.

There is a big argument as to whether you should deflate tyres or not in sand. Myself I do, I have a mate who never does, and he never has any problems.

Over here beach sand tends to need a different approach to desert sand. Most people in the desert here go low range with deflated tyres. It is not necessary to have diff locks, TC etc but if you have them you may as well use them (after all that's what you got them for). I have done the Simpson in both a S3 V8 stock standard and a td5 Defender stock standard...with no problems. Have driven on the beach with both also.

Beach sand can sometimes be easier tackled in high range.

To be honest, it varies from place to place and day to day, so it can always be easy to get it wrong

Thanks for all the info. Good to hear peeps different views.


TJ

I've also heard the argument about not deflating tyres. If you go fast enough I suppose.......
I also can't understand the logic behind it.
I put mine down to 20-23 psi as soon as I get on the sand, and it's usually okay from there. But 15psi has been used a few times.
All I know is that if I get stuck, then let my tyres down further, I get unstuck. That's the logic I use. And it's true there are many and vastly different types of sand and differences in the same sand at different times of day. Whatever works really.
However, if it was good enough for the Long Range Desert Group, it's good enough for me.

Thats good to know.

Although this doesnt effect me - if you were driving alot on sand / desert terrain would your vehicle be better off as a manual trans or auto? And are diesel motors better than petrol?


Jas

Some really go information there , an official pat on the back to you all.

The only thing I will add is the tip I gave a couple of weeks ago regarding buried ladders and trying to retrieve them - not much fun in high temperatures. If using sand ladders tie a length of strong nylon cord to the end of each ladder and the other to the rear quarters of your vehicle. When you pull away at whatever speed is right for the conditions the ladders simply follow. This can be some distance if you've got rolling and just can't stop as you're still powering though a sea of soft sand. Keep going until you reach solid ground. Never pull away and stop for your co-driver until you are 100% certain it's safe to stop. Far better the co-driver has a long trudge than having to dig out your motor again.

One more thing, make sure the lengths of cord are a good length - say 15ft long, even 20ft, just as long as they are not too short. Reason is that if you power away like in a Le Mans start (we all know it happens when a more measured approach is quite adequate), when the cord becomes taught and the ladders follow, they won't be able to catch you up and twat the back of your vehicle! Not likely with steel ladders, but those lightweight alloy numbers can really fly.

For me it's personal preference as to manual or auto box. Many say an auto is better as you're inclined not to get any wheel spin when setting off or changing gear and a smoother power delivery to the wheels. The drawback is they tend to get quite hot and often need an additional cooler. I'd prefer a manual solely for the 'user input' side of it.
I'd also prefer a diesel for the extra torque and lack of needing to change gear quite so often.

Tying sand mats - I saw someone do this when the rear wheels ran over the rope for the front mats and it pulled off the securing point on the car. I also saw someone having their car dragged to a halt as the rope tightened and attempted to pull the mats free. I've done it and would do it again, especially when I'm by myself (against all advice, I know) but sometimes it goes wrong.

I dont have any of the traction control etc obviously so cant comment! As said AT will be better than MT.

Tyre pressure - where is the debate? On soft sand there is no doubt - lower pressure (not by much as it goes) makes a huge amount of difference. For me in the Series landie it was the difference between struggling at 40MPH, or cruising at 55. For the Range Rover, being a heavier vehicle I guess, it was the difference between getting stuck, or being able to comfortably drive! On hard/compact sand there is no point in deflating the tyres.

Sand dunes are interesting. I think the most hairy ones we were doing was in the dark - spacial awareness and direction goes completely out of the window...and you want to give it some because you want to get to the top...but at the same time, there is always that "hmm" moment when you are going up! I guess the "proper" way to do it, is to walk first with a torch...but...hmmm, wouldnt fancy that for several miles myself!

Ive read a fue posts on a south african and australian off road forums and quite alot of them use the Landcruisers and patrols with 4.2 + 4.5 petrol engins. They say that the higher reving from the engine work better once you get up and going on the sand. And pritty much all of the trucks on those forums had at least 265 wide tyres. And another thing i noticed was that most people had a tyre called dick cepek radial FC II. Ive googled it and ive never seen one in the uk. Looks like a aggressive AT similar to cooper disco ST

Why 4.2 or 4.5 litre engines? Why 265 tyres?

Everything on an overland vehicle is a compromise.

Many Aussies argue that a Defender is underpowered. I would argue the opposite.

Aussie tend to carry far too much gear IMO. Cast iron cookware etc, electric pump for showers External shower screens etc etc.

One cast iron pot weighed more then my stoves, all my pots/pans etc. Would hate to imagine what their vehicles one. One guy had a 400/500 litre additional fuel tank on board because the tank come free!


Brendan

Heavier the vehicle the larger the tyres need to be to get same ground pressure.

4x4overlander wrote:

Why 4.2 or 4.5 litre engines? Why 265 tyres?

Everything on an overland vehicle is a compromise.

Many Aussies argue that a Defender is underpowered. I would argue the opposite.

Aussie tend to carry far too much gear IMO. Cast iron cookware etc, electric pump for showers External shower screens etc etc.

One cast iron pot weighed more then my stoves, all my pots/pans etc. Would hate to imagine what their vehicles one. One guy had a 400/500 litre additional fuel tank on board because the tank come free!


Brendan

Heavier the vehicle the larger the tyres need to be to get same ground pressure.

I see what you mean. And i did think the same thing but as there were alot of peeps with similar type vehicles and equipment it sounded like that was the proven way to go on the soft gold stuff. Could be just peer pressure like the uk " your ride must be a land rover or its inferior".

Well I use a 110 LR with a 300 TDi engine running on 255/85/16 BFG M/T. Mainly do solo trips. Longest trip was 8 months in Australia which included places such as Simpson desert after a sand storm which was fun.

Did not find the 2.5 litre diesel engined underpowered, too small, or tyres wrong type. Did not have any particular problems did have a great time however.

Horses for courses really.

Main thing is to get a mechanically reliable vehicle and equipped so that it sorts your purpose and needs.

Brendan






Brendan

That FC II tyre is a compromise tyre - and as 4x4 overlander said, it all has to be unless you spend all your life in one environment. That tyre is better on the road and better on rock (both which you get a lot of in Australia) than on sand.

http://www.offroaders.com/tech/AT-MT-Tires/Dick-Cepek-F-C-II.htm

A pure sand tyre looks nothing like that. But there is never a need for one for all the time. Most of the time overlanding is spent on other types of surface.
The difference between 265 and 255 isn't that much, especially when you've let them down a bit. And here's another thing - when you let a tyre down the area in contact with the ground increases - logical, yes? But it increases more lengthwise than width wise it has been said. So the higher the tyre profile the better as the contact area increases more along it's length than across its width. A wide tyre can't hurt, but a low profile wide tyre isn't a good thing they say. There needs to be quite a reasonable distance between the rim and the tread.
My tyres are 235/80R16 - they're not that wide but the '80' aspect ration means they are quite high and when I let them down the contact area increases a lot.

Unless you run and have no problem without letting them down, then ignore the above.

onlyMark wrote:

That FC II tyre is a compromise tyre - and as 4x4 overlander said, it all has to be unless you spend all your life in one environment. That tyre is better on the road and better on rock (both which you get a lot of in Australia) than on sand.

http://www.offroaders.com/tech/AT-MT-Tires/Dick-Cepek-F-C-II.htm

A pure sand tyre looks nothing like that. But there is never a need for one for all the time. Most of the time overlanding is spent on other types of surface.
The difference between 265 and 255 isn't that much, especially when you've let them down a bit. And here's another thing - when you let a tyre down the area in contact with the ground increases - logical, yes? But it increases more lengthwise than width wise it has been said. So the higher the tyre profile the better as the contact area increases more along it's length than across its width. A wide tyre can't hurt, but a low profile wide tyre isn't a good thing they say. There needs to be quite a reasonable distance between the rim and the tread.
My tyres are 235/80R16 - they're not that wide but the '80' aspect ration means they are quite high and when I let them down the contact area increases a lot.

Unless you run and have no problem without letting them down, then ignore the above.

I see what you mean. I didnt think that the height of the tyre would be a factor in the area contact of the tyre when deflated. But it makes sence.
Good info on this subject and like ive mentioned before i dont have much overland experiance so your knowledge is my knowledge, and im learning. Thanks all.


TJ

The best thing about knowledge/advice is that it's best to take in all you can - and then ignore it and do what you feel is right. The reason is that there is just so much of it and not all of it, including what I say, is always right.

Some interesting questions:

Yes the Defender is underpowered by a considerable margin, but it is not how much power you have it is how you use what you have, and the Defender like the Shogun and many other allegedly "low power" vehicles use their power efficiently due to the correct gearing for a variety of conditions, and allows a considerable driver input in selection. It comes down to the usual statistics, manufacturers use power output as a marketing tool to sell vehicles, but we have to understand why these vehicles are allegedly low powered.

Manufacturers use generic engines, these are usually electronically controlled for power, while a 4X4 has lower power it has it for a reason, this is higher low end torque, or a flatter torque delivery over the same engine used in a higher power application, as this loses some of the lower end torque to the detriment of full power. Most engines very rarely use full power anyway, so it is what it is, worthless marketing spiel designed to sell a vehicle, so it comes down to the compromise again.

Petrol V diesel - in sand the petrol may have a slight advantage, but it depends on the sand type and ultimately the driver and how they can handle their vehicle, with a petrol kept at high revs it gains this advantage, as soon as it hits more drag the engine revs drop dramatically and it can ultimately bog a vehicle down. Diesels have fewer revs and more torque and are not prone to dropping engine revs so easily as petrols, so both have advantages and disadvantages, and ultimately it comes down to a combination of driver and vehicle working in harmony.

Auto V manual - difficult, manual boxes give better control than earlier autos which is a positive and a negative as too much acceleration can dig them in, not enough acceleration means they sink and build up a sand wedge in front of the wheels. Autos have a smoother power delivery which reduces these problems, earlier autos lack the sophistication of modern autos and are often worse than manual boxes.
Modern electronically controlled autos have a range of facilities to match the transmission to the engines power, torque, and revs; and ensure it is much easier to drive on sand and other soft surfaces, also a number, the Shogun included, have a tiptronic manual override so it can be used as a manual with the benefits of the automatic.

For me it is the automatic Shogun instead of the manual.

It is ultimately down to a number of factors and compromises, where do you draw the line, how good a driver are you, and how well do you know, and can drive your veicle. It is something only you can answer.

Very good pointers assasin.

Im a big fan of the shogun auto. IMO the 3.2 turbo diesel in the current shogun is one of the best engines made.

I agree with the section were you talked about 4x4 having lower power but correct gearing for the conditions. My Hyundai is a 2.9 commom rail merc engine and it has 160bhp, Compared to modern engines of a similar size what are getting in to 200bhp+ the hyundai produces relatively small bhp. I have towed caravans and off roaded with many modern 4x4's and IMO they dont tow any better or peform better on adverse terrain than what ive got, and if anything i find that my "Under powered" low geared Terracan has more controll at low level speeds. - Hope this makes sence.

It makes perfect sense to most of us experienced in driving in most conditions, with the lower power you can gear a vehicle down to use the bottom end torque and still have very low speeds, it is this low speed which gives us control in difficult driving conditions such as hill climbs and descents, ot traversing rocky terrain where low speed is essential.

Cars with the same engine do not need this control and are higher geared with higher power outputs, if they tried to ascend or descend the same hill as a 4X4 they would run out of power on the way up, and lose control through "runaway" on the way down.

On a personal note my Shogun is also 160 BHP, but has more weight to pull than your vehicle, but both our vehicles will do pretty much the same job, and my Shogun has thumping torque from tickover, when off road it rarely needs any more then 1400RPM to tackle any terrain due to its high bottom end torque and auto transmission which is well matched. We can both tow high weights due to the correct gearing, and the same applies to most low power vehicles such as the Defender which can also tow well over 3 tonnes, yet still give us total control in all off road driving conditions.

Assassin wrote:

It makes perfect sense to most of us experienced in driving in most conditions, with the lower power you can gear a vehicle down to use the bottom end torque and still have very low speeds, it is this low speed which gives us control in difficult driving conditions such as hill climbs and descents, ot traversing rocky terrain where low speed is essential.

Cars with the same engine do not need this control and are higher geared with higher power outputs, if they tried to ascend or descend the same hill as a 4X4 they would run out of power on the way up, and lose control through "runaway" on the way down.

On a personal note my Shogun is also 160 BHP, but has more weight to pull than your vehicle, but both our vehicles will do pretty much the same job, and my Shogun has thumping torque from tickover, when off road it rarely needs any more then 1400RPM to tackle any terrain due to its high bottom end torque and auto transmission which is well matched. We can both tow high weights due to the correct gearing, and the same applies to most low power vehicles such as the Defender which can also tow well over 3 tonnes, yet still give us total control in all off road driving conditions.

Totaly agree. Its good to hear other peoplae say this instead of me just thinking it.

Like you mentioned with the 1400rpm, i have also found this with my truck. Mine is also matted to a auto trans. Ive found when i have gone off road or greenlaneing that if i do go over 1700rpm the turbo kicks in, the wheels start spinning and it becomes less controlable especialy in mud.

From what I have seen, most trouble on sand is caused by so called overlanders trying to drive a mobile hotel, so I would start by taking 1/2 ton tat out of the truck.

Do not have that problem, with so much low end torque the turbo comes in very progressively, in normal driving you cannot tell it has one.

Assassin wrote:

Do not have that problem, with so much low end torque the turbo comes in very progressively, in normal driving you cannot tell it has one.

I would'nt say it was a problem just that ive noticed when the engine is 1700rpm + and the turbo comes on that the wheels are more prone to spinning than under 1600rpm when your just using the engines torque.

On occasion I have found that this is quite useful when the tyres are full of mud, a little rev and the tyres spin and shed the mud. Got nothing to do with sand tho. I imagine this would just dig a hole.