My NOT so good 4WD video clip

Submitted: Wednesday, Jan 26, 2011 at 22:48
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Reply By: River Swaggie - Thursday, Jan 27, 2011 at 01:03

Thursday, Jan 27, 2011 at 01:03

If you take an air compressor with you and drop your tyre pressure to say 25psi the front and 27psi back you wont get any of that wheel spin in that situation,plus its better for your tyres, suspension (smoother ride),rocks etc etc....

Look at the 4psi rule too...Although i dont use it much and havnt had a puncture (probably shouldn't hav said that lol) throughout our High Country on many trips..
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Follow Up By: PradoMad - Thursday, Jan 27, 2011 at 06:02

Thursday, Jan 27, 2011 at 06:02
whats the 4psi rule?
I had the pressure down to about 32. However those gauges are not very reliable. Went to pump it up before heading home and it showed 38psi at the servo ??!!
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Follow Up By: Member - Graham H (QLD) - Thursday, Jan 27, 2011 at 08:44

Thursday, Jan 27, 2011 at 08:44
The 4lb rule is check your tyres cold as in first thing in the morning. Check them again half an hour down the road. They should be 4lb higher

If not pump them up a bit more Under inflated tyres heat up more

When towing I work on 6lb and they have stayed good for 60,000k so far.

You have learned that no two gauges are the same.

If you use the above rule what the gauge says doesnt really matter as its all relative to loadings temp etc.

I have a TPMS and two gauges Only 1 agrees with the TPMS so I use it.

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Follow Up By: Member - John and Val - Thursday, Jan 27, 2011 at 08:57

Thursday, Jan 27, 2011 at 08:57
I'd agree 100% with Swaggie, though the actual pressures you use depend on a lot of factors, especially type of tyres and loading. With fat tyres I use 30-35 psi (when the tyres are cold) on bitumen for our Troopy, and I'd drop to about 22-25 as Swaggie suggests in the sort of conditions in your movie, maybe down to about 18 if necessary. I usually think in terms of % of bitumen pressure - I go down at least 25% on rough gravel, 50% for very loose or sandy. As well as more comfort for vehicle and occupants, the aim is to increase traction through increased footprint - half pressure will roughly double footprint.

Last resort for me is about 10-12 psi. Below that there is real risk of the vehicle actually walking out of its own front tyres. At such low pressure you must drive slowly and steer very gently.

The 4 psi rule - basicly, run your tyres at a pressure where they flex enough to warm up so that the pressure rises by about 4psi. It's a very rough guide, since there are so many variables - hot bitumen, sun shining on tyres, etc , but useful to get a feel for what's about right.

It's important to drop your speed when running at reduced pressures. Certainly never attempt highway speed without highway pressure!

Agree completely with your comment about the accuracy of gauges. Recommend don't use an ultra cheap one, but use the same one consistently as your reference. Every gauge is different, but consistency is more important than absolute accuracy.



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Follow Up By: Allan B (Sunshine Coast) - Thursday, Jan 27, 2011 at 11:38

Thursday, Jan 27, 2011 at 11:38
PradoMad, It is quite possible that there is nothing wrong with your tyre gauge. When you set your pressure at 32psi were your tyres fairly cool? Then on arrival at the servo you probably had been driving at reasonable speed for a time and your tyre pressure had increased to the 38psi you observed due to heat build-up.

Next time at the servo compare your gauge indication with what the servo gauge shows. You may find only 1 or 2psi difference and that is to be expected. If there is more than 1 or 2psi compare your gauge readings with some other gauge.


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Follow Up By: Patrol22 - Thursday, Jan 27, 2011 at 17:53

Thursday, Jan 27, 2011 at 17:53
Personally I believe the 4psi rule simply wouldn't cut it in this situation and nor would I even consider using it. Judging from the loose service, and that I would be in low range with a peak speed of around 50kph (not in this case mind you) I would simply drop pressures to around 25psi and then pump up again before exceeding 80kph....but in any event prior to getting back on quality gravel or bitumen. The 4psi rule is not just proportional to flex in the side walls, although this will increase temperature and pressure, the greatest contributor to exceeding the 4 (some also say 6) psi rise is speed. So, if you are dropping pressures it is always advisable to drop speed also.
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Follow Up By: Patrol22 - Thursday, Jan 27, 2011 at 17:54

Thursday, Jan 27, 2011 at 17:54 pointed out by John above
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Follow Up By: jschacher1 - Thursday, Jan 27, 2011 at 18:56

Thursday, Jan 27, 2011 at 18:56
Great advise ALLAN B
thank you
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Reply By: Fab72 - Thursday, Jan 27, 2011 at 08:33

Thursday, Jan 27, 2011 at 08:33
Nice video. Shows the inclines really well. Looks like you had a ball.
I have often taken videos of steep climbs only to get home and it looks flat.

Like the "pimp" music towards the start....hehe.

AnswerID: 443176

Reply By: landseka - Thursday, Jan 27, 2011 at 10:47

Thursday, Jan 27, 2011 at 10:47
Hi PradoMad

When you get more experienced at 4x4ing you will learn the safer way to descend a steep hill when through lack of traction OR power you lose forward motion going up.

This involves using your brakes gingerly or not at all to come to a full stop, engine off and hanging in gear. Low range of course. Then reverse gear is selected, clutch out still hanging on the gearbox, touch the key to start the motor in reverse gear. Then you will slowly go down the hill fully in control unlike the out of control backslide with wheels locked that I saw in that video.

I did enjoy your video, you captured the steepness of the climb which is so often hard to do to explain to anyone who has not been there.

Cheers Neil

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Follow Up By: jschacher1 - Thursday, Jan 27, 2011 at 17:17

Thursday, Jan 27, 2011 at 17:17
excellent advise, thanks
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Follow Up By: nickb - Friday, Jan 28, 2011 at 11:41

Friday, Jan 28, 2011 at 11:41
I thought that the Prado was auto, therefore this technique would not work? Maybe my ears are failing me haha
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Reply By: Member - Jack - Thursday, Jan 27, 2011 at 15:41

Thursday, Jan 27, 2011 at 15:41
The video was fine. If you are looking for a James Cameron 'Avatar', then you fall sadly short. But if you want a nice momento of a trip it was good. It seems you were cameraman and main star all in the one shoot, and if that is the case, you did very well.

Just keep plugging away. You will improve in the areas where you wish to improve.

Good luck.

The hurrieder I go, the behinder I get. (Lewis Carroll-Alice In Wonderland)

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Reply By: dublediff - Thursday, Jan 27, 2011 at 16:12

Thursday, Jan 27, 2011 at 16:12
The four pound is the "michelin or pirelli rule" I forget which. But it also mentions that all tyres should heat up to 'about 4 lbs' if correctly inflated for the prevailing conditions....speed, load, terrain will all affect this. Off road at slow speeds it doesn't have much relevance. You let your tyres down to the level required for the conditions and drive to the conditions.

How the michelin (0r pirelli) rule impacts is on formed roads at sustainable speeds, such as travelling to and from the off road activities. If the tyre pressure increases to less than about 4lbs you are overinflated, ie tyres not able to flex sufficiently to keep the optimum foot print contact with the road and also causes excessive tyre wear to the centre of the tread, and if it inflates more than 'about 4lbs, then it is underinflated and will cause premature casing deterioration and possibly blow out whilst on the move.....ever seen a truck driving with one of the tyres 'smokin' then you have seen an underinflated tyre (unless his airbrakes have locked on). I have actually seen a small sedan with this issue on the West Gate Highway some time back, I tried to warn to driver but she must have thought I was trying to hijack her....oh well...

AnswerID: 443208

Reply By: Dasher Des - Thursday, Jan 27, 2011 at 17:26

Thursday, Jan 27, 2011 at 17:26
I also enjoyed your video. It looks nice country there wherever it is. Can you give us a location?
We must have bought our side steps at the same place. Mine have that little upwards bend in the middle too LOL.
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Follow Up By: jschacher1 - Thursday, Jan 27, 2011 at 18:58

Thursday, Jan 27, 2011 at 18:58
very observant!
Video was shot in BRIGHT VIC. Awesome country!!
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Reply By: jschacher1 - Thursday, Jan 27, 2011 at 19:04

Thursday, Jan 27, 2011 at 19:04
Thank you all for your advise, recommendations, comments, praise etc....

Prado V Pathfinder[/url]
this is an earlier version (poor quality)


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