If you can't lower your tyre pressure, can you at least engage 4WD!

Submitted: Tuesday, Jan 17, 2012 at 02:05
ThreadID: 91257 Views:4138 Replies:11 FollowUps:20
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Once again over the Christmas break I encountered my pet hate - an unnecessarily corrugated and chopped up track and then after about 10km, a vehicle stopped in the middle of it, sort of half bogged and the driver out twisting his hubs in.

He was most surprised when I suggested to him that if he did this at the start of every track he ever drove down, they might all be a lot smoother.

Even threw in the old furphy about saving fuel! How you save fuel by driving in 2WD in soft sand with palpable wheel slip I'm not sure.

I think it's time to start a campaign where every sign on every track that refers to caring for the track, tyre pressures etc, ought to start with an instruction to PLEASE ENGAGE 4WD NOW.

Ought to be common sense, but it don't seem too common these days.

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Reply By: Member - Bucky - Tuesday, Jan 17, 2012 at 05:23

Tuesday, Jan 17, 2012 at 05:23
Better idea

Take the 4x4 off them

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Reply By: Bushranger1 - Tuesday, Jan 17, 2012 at 06:24

Tuesday, Jan 17, 2012 at 06:24
G'day Paul,

My pet hate is people who don't reduce their tyre pressures or engage 4wd in the deep sand.
Just recently I stopped a vehicle in the mallee to advise him to reduce his tyre pressures because there was a soft sandhill ahead. He said "nah can't be bothered pumping up the tyres again later". Consquently he got stuck on the sandhill & all the vehicles behind had to stop. Then he had several more attempts ripping up the track in the process.

They wonder why Parks Victoria close tracks to 4wd's & we get a bad name!
AnswerID: 475165

Follow Up By: Snowy79 - Tuesday, Jan 17, 2012 at 09:15

Tuesday, Jan 17, 2012 at 09:15
It's at times like those that you wish you had the old Dirty Harry 44 magnum, shoot out all 4 tyres, that'll solve the pressure issue.

Don't mind educating people, as I do recall I was once an inexperienced 4WDer, but those that know better and choose not to, do annoy me.
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Follow Up By: Allan B (Member, SunCoast) - Tuesday, Jan 17, 2012 at 09:35

Tuesday, Jan 17, 2012 at 09:35
With some it is a badge of honour to remain in 2WD.

"Yair, went right through on two wheels mate... no f- worries"
Leaving behind a damaged track for those following!

The Southern faces of Goog's Track are really badly scalloped.

But it's probably a waste of time to carry-on about it here. Those who behave in this way are unlikely to be reading it here. Or if they did, would take no advice.


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Follow Up By: wato35 - Tuesday, Jan 17, 2012 at 10:00

Tuesday, Jan 17, 2012 at 10:00
A little advise please.
I don't get out too much, but I know to drop tyre pressure and use 4 WD drive when required.
But the corrugated roads have me beat. I travelled on the Rail Road from Tom Price into Dampier and also Broome to Cape Leveque. They where very bad, I dropped pressure to about 25 PSI. I was knocked around no matter what speed (or lack of). Other vehicles were passing me at ease. I was in a 2006 Hulux with a CT.

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Follow Up By: Member - shane c5 - Tuesday, Jan 17, 2012 at 10:16

Tuesday, Jan 17, 2012 at 10:16
This is a fascinating topic. The Cape Leveque road is corrugated to hell in parts. So what speed to drive at, what tyre pressure and what about cornering. The 25 psi would have been find as the trye soaks up some of the pressure. As for speed what you try to do is get the speed right so that you are skimming over the top of the ruts. This is were it gets interesting, if you are doing this, then you are partly airborne while driving. They did a test in USA and came up with the little fact that at 83km/h this was the safest speed to drive over corrugations!Well, maybe for the type they were using for the test. Not to mention tyre size (will leave this out). Your drive speed will be determined by the size and height of the corrugations as well as distance betweem each mound. On the Cape leveque road, you may find that 50km/h is the most comfortable, or it maybe 60? You have to judge this and bear in mind that the faster,than the harder the car is hitting the road and therefore more damage can occur. Remember the airborne bit, well when cornering, being airborne means no traction and therefore if you are too fast you get either front wheel skid or rear wheel skid. Both can roll the vehicle, or put you up a tree or into an oncoming vehicle. So for corners, you have to slow down. Rougher, but really worth it. As for being passed, who cares as long as they don't spray you with rocks. Not to mention that they probably aren't seeing anything. Lastly, the faster you go the worst you make them.
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Follow Up By: Member - Serendipity(WA) - Tuesday, Jan 17, 2012 at 10:19

Tuesday, Jan 17, 2012 at 10:19

You did the right thing dropping tyre pressure on corrugated roads - it will make the ride mildly softer but they will save the shockies from a lot of extra work where they might overheat and fail.

As for others passing with what seems like ease - well no they are not at ease. When some corrugations are not that far apart you can sit at 60 to 80km and get a general vibration / rattle that you might live with. I often find I don't want to destroy my car and camping gear and just slow right down. Further when traveling at any kind of speed on corrugations you run the risk of bouncing yourself off the road - you really have no grip on the road and can sort of aquaplane into the bush.

Don't worry about people (who might not even own the car) smashing it over rough roads. We were slowly working our way across the gunbarrel years ago when a range rover came other direction at 80+km barely controlling his flight. Would have done the gunbarrel in 1 or 2 days. Or not. We suffered enough damage from worn parts and we were going dead slow.



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Follow Up By: Alloy c/t - Tuesday, Jan 17, 2012 at 12:04

Tuesday, Jan 17, 2012 at 12:04
Dropping tyre pressure to increase the ' footprint ' and therefore traction is one thing , dropping tyre pressure to change ride comfort over corrugations is another thing entirely , less air pressure in the tyre increases the heat of the tyre dramaticaly and can lead to premature failure far quicker than a correct spring and shock combination will fail.
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Follow Up By: Life Member - Phil B (WA) - Tuesday, Jan 17, 2012 at 12:49

Tuesday, Jan 17, 2012 at 12:49
Hi Watto,

Travelling on that road can be very rough. The vehicles sailing past you were probably those amazing mining vehicles that seem to be able to do incredible speeds and carry enormous loads - lol.

You did the right thing by slowing down and letting your tyres down. That way your vehicle and teeth will last a lot longer.


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Follow Up By: Bushranger1 - Tuesday, Jan 17, 2012 at 12:53

Tuesday, Jan 17, 2012 at 12:53
Very true. These are 2 different situations.
I drop my pressures down on corrugations but not to the same degree as I do in deep sand.

I soon learn't though with split rims reduced pressure on corrugations does not work real well as far as damaging the tubes due to the increased tyre flex. Works well with tubless though as there is less heat produced with tyre flex as long as you don't go too low.

Whats the best pressure? Hard to say due to all the variables involved but if you learn to "read" your vehicle you will find a good compromise for sand or corrugations.
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Follow Up By: Member - Blaze - Tuesday, Jan 17, 2012 at 14:15

Tuesday, Jan 17, 2012 at 14:15
Gady Watto,

As I think most have mentioned in inferred to. It depends a lot on what you call a smooth ride, some don't mind bouncing from one side of the road to the other. I have always found with the right tyre pressure and in 4WD not to many places that you can't find a ggod comfy speed, I exclude the Anne Beadell Highway from that comment LOL. Also it depends on the weight of and in your vehicle and also a huge part of the equation is what tyres you run, (Wall thickness and construction) being a major influence.
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Follow Up By: Snowy79 - Tuesday, Jan 17, 2012 at 20:26

Tuesday, Jan 17, 2012 at 20:26

Working up in the Pilbara at the moment I travel the Dampier to Tom Price road from time to time, was out there last Sunday, and with my job probably spend more time on the dirt than bitumen.

A few people may frown upon what I say but it depends on how much dirt road driving experience you have and how comfortable you are driving with a bit of wheel-spin and the odd slide. I generallly drop tyre pressures to somewhere between 24-28 psi depending on how far and fast I will be going. You then get up to a speed where as previously mentioned you begin skipping over the corrugations. BUT this does reduce traction, so the vehicle will sometimes skip sideways, and give a bit of oversteer or understeer in the corners, if you are confident and comfortable in being able to correct this fine, if you have any doubts then best to slow down.

Also as previously stated comfortable is a relative thing, what some people call a comfortable ride, others may call rough. Also if you are towing a trailer or have a particularly top heavy vehicle the above is not reccommended.

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Reply By: Peter_n_Margaret - Tuesday, Jan 17, 2012 at 09:49

Tuesday, Jan 17, 2012 at 09:49
If the OKA is off the black top, 4WD is engauged!
If for nothing else, the braking and handling is better and safer.

The OKA had no free wheel hubs when we bought it and I had them fitted. I now consider that to be a mistake. The fuel consumption difference is almost zero.

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Follow Up By: Member - Matt M - Tuesday, Jan 17, 2012 at 10:15

Tuesday, Jan 17, 2012 at 10:15
Agree with you wholeheartedly Peter. I converted my previous car (80 series) to part-time 4WD. While there may have been a difference in fuel consumption, it was beyond my ability to measure outside of a laboratory.

But the main reason I regretted the decision was the handling on loose surfaces (not just serious 4WD tracks). It was a completely different vehicle on any gravel with 4WD engaged.

Have another full-time 4WD now, and not going to make that mistake again.


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Follow Up By: Member - Paul B (WA) - Tuesday, Jan 17, 2012 at 12:47

Tuesday, Jan 17, 2012 at 12:47
Interesting thing a shire engineer told me years ago not long after the 80 series GLX & Disco's with their full time 4WD became popular with farmers in his area - you could tell every single one of them that had one because the gravel road adjacent to their farm gate stopped getting corrugated, where they accelerated away.

Just proves that wheel slip is what is primarily responsible for corrugations. I remember meeting a big tagalong group on the Anne Beadell once where EVERYONE had to be in 4WD with tyres deflated appropriately and the track was completely different behind the convoy (of about a dozen) as it had been in front of it - like it had been graded.

So I'm with you Peter & Matt, my Prado, being full time was always in 4WD, but my Pajero now is too. I can't discern a fuel consumption difference in the Paj between 2&4WD on the highway. A mate who's now done over 200,000km in a similar Paj says he can't discern a difference in tyre wear either.
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Follow Up By: Wilko (Parkes NSW) - Tuesday, Jan 17, 2012 at 18:43

Tuesday, Jan 17, 2012 at 18:43
When I get off the black top I usually put it in 4wd and i agree that only poor simple deluded fools try to do a 4wd track in 2wd, It isn't a badge of honour its a badge of stupidity. But Id like to install freewheeling hubs on my Hilux, I use it unlocked on road when towing heavy loads down hill etc.

Cheers Wilko
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Reply By: member - mazcan - Tuesday, Jan 17, 2012 at 11:22

Tuesday, Jan 17, 2012 at 11:22
hi paul b
while i agree with your thread
putting up more detail on signage wont make an ounce of difference to most idiots as most dont read/cant read or dont understand what the signs are saying
or just as likely to knock the signs down for something to do with their bullbar
there is a big precentage of idiots on all roads and tracks and the only thing thats thinning them out together with a whole lot of unfortunate victims is sadly accidents
so its a losing battle all round with these d/heads
we'd all like to know a solution to the above problems ???????
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Follow Up By: Bushranger1 - Tuesday, Jan 17, 2012 at 12:43

Tuesday, Jan 17, 2012 at 12:43
G'day Barry,

When I told the guy in the Mallee that he should let air out of his tyres there was a sign 500 metres back that he had passed that said "Deep sand 4WD only".
Can't spell it out any better than that!

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Follow Up By: Member - Paul B (WA) - Tuesday, Jan 17, 2012 at 12:58

Tuesday, Jan 17, 2012 at 12:58
Yeah you're right about the idiots who simply don't read the signs, but very few of the signs do make the obvious point about protecting the track by using 4WD.

I think there are a lot more inexperienced drivers who simply need the point being made. Even if you don't want to let your tyres down for whatever lame reason, you are going to do a lot less harm to the track in 4WD.

Trackcare don't really even emphasize how actually engaging 4WD, whether you think you NEED it or not, is a great way to protect the track.

I just think if we did this a lot more, we'd have better tracks and maybe even start to break down the '2WD badge of honour' thing that we've all encountered, usually on a chopped up track.
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Reply By: Kris and Kev - Tuesday, Jan 17, 2012 at 16:38

Tuesday, Jan 17, 2012 at 16:38
Our cruiser is fairly idiot proof being all wheel drive. But I do drop the tyre pressures to suit, being on sand, rocky or corrugated roads. Last trip on the Gibb River Road, and particularly on the Mitchell Plateau Road, on bad corrugations I experimented with tyre pressures and speeds and found the lower tyre pressure and sitting on around the 80 k/h was the best ride, not only for our vehicle but also for the camper trailer. I did try slower speeds, but that just shook the crap out of the cruiser and trailer. I had no problems with vehicle drift bit had to really concentrate watching for dips and crossings. Came across one tag a long group who did not slow down on the crossings and they copped tyre damage a few times. (This group did get to be well known by other travellers and did not endear themselves!)
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Reply By: bob smith 1 - Tuesday, Jan 17, 2012 at 17:19

Tuesday, Jan 17, 2012 at 17:19
A sign on every track, no way ! We go bush to get away from lights, signs etc.
What I dont get is why do even flat roads have shocking corrugations, this would have nothing to do with pressures, would it.
AnswerID: 475211

Follow Up By: Member - shane c5 - Tuesday, Jan 17, 2012 at 23:06

Tuesday, Jan 17, 2012 at 23:06
Another great question, corros are formed not by one process but by serval all at the same time. !) speed, the faster you go the more dust you raise and therefore the more dirt moved, 2) the road soes actually stick to the tyres for a period of time, usually nanoseconds, as the yre goes round, pebbles, quartz and the likeare picked up by the tyre and fall off in a rythem due in part to the shochies, the fall off in the grab and bounce caused by the vehicle travelling over them,, 30 the dust rised then catches on the small build up of "rocks" for the sake of the exercise which slowly/quickly builds up the mounds of dirt that form corros. The Mitchell Plateau road, actually the Port Warrender road is a great example and some of the most amazing corros you can encounter, is made up of small nodules of Iron Oxide as it is a lateritic soil, if you got out of the car, you can with a little difficulty, kick the corros over as they are just mounds of dirt. Do this with clients all the time. If people slowed down, the corros would take longer to form, but form they will.

Another but different example is coming out of creek crossings and speeding up the hill. The tyres and suspension, have different jobs. The shockies are design to keeep the tyres on the road. The drive thru the tyres, works against this and dig. So presdure is exerted thru the tyres for traction, the shockies try to hold the tyres down, but push and release the pressure causing corros up the hill. If people just cruised up the hill, these corros wouldn't form at all. 4wd is benefitial in this case. Most evident on the track into the bungles. When you go down the hill, these are a bloody nightmare.

So corros form for many different reasons, depending on, soils, speed, and terrain.
shane c5
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Reply By: Member - Michael John T (VIC) - Tuesday, Jan 17, 2012 at 20:06

Tuesday, Jan 17, 2012 at 20:06
There is a sign on the track out to Steep Point WA 4WD and reduce tyre pressure to 20 psi, penalties apply by the Range for non compliance.

Good thing to remind travelers, remember we all have differing ideas on the subject. A sign makes it clear what is expected. That said there will always be those who 'know better".

AnswerID: 475226

Follow Up By: ross - Wednesday, Jan 18, 2012 at 19:43

Wednesday, Jan 18, 2012 at 19:43
I wish he would start fining them. Every second driver on the Steep Point Road seems to be an idiot that either wont deflate his tyres,or has to do 80klms+ all the way back to the bitumen
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Follow Up By: Hairy (WA) - Thursday, Jan 19, 2012 at 11:48

Thursday, Jan 19, 2012 at 11:48
Ive seen signs like that before. One track I go down regularly says to deflate your tyres or cop a $200 penalty, but it really cant be enforced.
I think you would fine that none of them are legal really.............what would happen if some one had an accident and their tyre pressures were below manufactures specifications?

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Follow Up By: get outmore - Thursday, Jan 19, 2012 at 11:57

Thursday, Jan 19, 2012 at 11:57
for a fine to be enforced it has to be in government legislation

otherwise best they can do is pursue you for breach of contract (by entering and passing the sighn you have a contract to abide by their conditions)
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Follow Up By: ross - Friday, Jan 20, 2012 at 03:06

Friday, Jan 20, 2012 at 03:06
They have all encompassing laws which read like "failure to comply with a notice"
I imagine its similar in the way health and safety notices are issued.
Another similar situation would be where C.A.L.M(WA) issue orders forbidding the general public to enter areas being logged to keep protesters out.

Parliament passes an Act which gives govt depts the power to prosecute.
Govts do this to save money and time by not having to invent a new law for everything.

I imagine it would also be illegal for a govt dept to put up signs saying they will fine you when no such power exists.
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Reply By: Member - Robert R1 (SA) - Tuesday, Jan 17, 2012 at 21:15

Tuesday, Jan 17, 2012 at 21:15
I think a sign would be a good idea. A lot of people new to 4wding will not know to engage 4wd when off the bitumen. I didn't. I learnt it on this site. I always drop pressures and engage hubs and 4wd when off the bitumen. I find the Hilux sits a lot better on the road.

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Reply By: Member - Richard H - West NSW - Wednesday, Jan 18, 2012 at 17:50

Wednesday, Jan 18, 2012 at 17:50
A couple of years ago went to Fraser Island.

The FWD I had was fitted with a winch, I should have charged $10 a pull, because it would have paid for my trip.

What appears to occur is a lot of the overseas people come here and hire a 'Fritz in a Britz' troopy or whatever, and hit the soft stuff, and down they go.

Of course there's lot of sand driving in Europe, and the hirer's don't give a 'rats', so long as you have a driver's licence.
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Reply By: snailbait (Blue mntns) - Wednesday, Jan 18, 2012 at 21:57

Wednesday, Jan 18, 2012 at 21:57
I agree with all of the comments but i would add that on loose corrugated roads i always put the vehicle into centre diff lock. This helps the tracking around corrugated corners also you have more control.
The speed varies on different roads that are corrugated in SA i came across a road that had corrugation's that were about 225 mm( 9 inch ) deep nothing stopped the teeth rattling
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Reply By: BluePrint Industries Pty Ltd - Thursday, Jan 19, 2012 at 12:33

Thursday, Jan 19, 2012 at 12:33
Hi Paul,

Yes people who don't drop pressures or engage 4x4 just because they believe their car is big enough and tough enough to do it in 2WD at road pressures are a pain, and also cause a lot of track damage.

We published a general guide to 4x4 tyre pressures and the reasons why you should lower pressures on a blog here a couple of years ago.

http://bit.ly/SandDriving It has some good tips for sand driving and also general off road driving regards tyre pressures.

It doesn't fix the problem, but it does give newer 4x4 drivers an idea of what they should do and why.

Everyone must also be aware of the dangers that come with lowering tyre pressures, such as tyre damage, the need to drive at lower speeds, and to avoid making really sharp turns at speed.

On a recent beach trip we had a few guys get bogged even tho they had lowered their tyres to 15 - 18PSI, after a bit of work and getting them to lower them to 12 for the really soft stuff most of them just drove out. Most where amazed at the difference the extra 3 PSI made.

Also remember if your going to let tyres down you also need a reliable compressor to reinflate them.



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