tyres

[nuozzie]

Hi All
I wonder if you can help me being a newbie, what psi do I need to run my Nissan x trail on gravel roads/mud/sand/rocks
I am just starting out on this 4x4 game so all info would be welcome.
Paul

[Squalo]

Hi Paul

It can depend on what tyres you have, but in general - for mud, rock and really rough gravel/dirt, 24psi works well, and for sand try 22psi and if you still struggle go to 18psi. You can go lower than that in an urgent situation but learn how it behaves at those settings first.

[nuozzie]

Thanks for the info I still have a lot to learn so there will be more questions as I go , once again thanks for the help
Paul

[GU_Thomo]

Remember, on the low pressures drop your speed to keep the tyre temps dow and do not make sudden turns.
You can roll the tyre off the rim.

Cheers
Parry

[tigga27]

G'day nuozzie,
you'll get a lot of info from different experiences which may become a little confusing but these guys are right. If you lower your pressures you need to slow down because due to the flex created in the tyre from being at low pressure it will heat up in the tyre wall and potentially cause a blow out. If you are on standard rims and tyres or close to it I personally would recommend not going below 18 psi and if you go that low go slow and try not to hit rocks too hard or corner hard in sand too hard or you'll damage the rim or roll it off the rim. Your car is a little lighter than my cruiser so in harder scenarios you may have to run slightly lower to get the same tyre spread. more spread=more friction and less pressure holding the bead in place. As an example I towed my campervan on fraser without trouble with the car at 20psi and the van at 25psi. I have attached a copy of a tyre guide I think the guy at the oodnadatta track roadhouse gives out for driving OT. Can't remember where I got it. Like I said, others may run different and have a different opinion but here's mine and I'm always happy to listen to others.
cheers
tigga

[WilSurf]

What?? Only dropping to 22psi on sand?
I go straight to 15psi and if it is very soft, go down even more.
The lowest I had was 7 psi going up a winding sandy hill. On top, reinflated it back to 15.

[nuozzie]

Thanks everybody for you help, thanks tigga that drawing is very good i will keep that.
Paul

[ozbogwam]

In my Sierra on 34s I would go as low as 4psi but usually around 8-10psi.

In my GU on 33s offroad in mud, rocks, sand or snow about 16psi

[BigJules]

I think you've received some slid advice above. The question is somewhat a piece-of-string one, as the appropriate pressure depends on the weight of the vehicle, type of tyre, the terrain etc. Use above as a guide. If you get stuck on the sand for instance, drop some more pressure until you can drive more easily. I tell everyone I'm running 20psi and go straight to 12-15  .

Cooper Tires have put out some informative video, though a quick Google ddin't bring up a link for me. These talk abotu measuring the legnth of the footprint. I wonder if anyone ever did that, but the general info is excellent.

[nuozzie]

Hi
I guess everybody is different in their ideas as what psi one should use but I think everybody says about 22 on average so if I go there then hopefully I should be ok.
anyway thanks for the info.
Paul

[tigga27]

exactly right Bigjues. Feel the car and the response from the tyres. lots of variables.

[Squalo]

Yeah you can easily go lower than 18psi on sand, but I think you should go in stages rather than just blindly use the same pressures all the time. For example I dropped to 22 on Fraser a year ago and thought I'd hit the right pressure (was well laden so had to take the vehicle's weight into consideration - probably 3.5 tonnes all up) then got talking to a local tour operator with a Hummer who said he was running 35psi with no problem...

Lower pressures mean higher fuel consumption.

The other thing for Paul is this - if you are driving along and do come to a stop due to traction problems, especially on sand, the first thing to do is to try to reverse out - not put the foot down and try to go forward, which in many situations will just dig you further in. On sand especially you will find that you should be able to reverse out, then try plan B.

Plan B might involve another go with more speed - in sand and mud, momentum is your friend.

Or a different route, or another tyre pressure drop, or some track building... you make it up as you go along.

I've learned heaps simply by driving with more experienced offroaders. Suggest you join a vehicle-specific forum and see if you can get out on a day trip with a few members.

[WilSurf]

Members of our club went on the CSR a few years ago.
On the radio they heard a group of cars having trouble getting over a dune.
They asked them what their tyre pressures were. The reply was: "we let air out and are low on 34"
The club members told them to go to 25 or even lower.
They did and got over the dunes easily.

But you are right, it all depends on  the car and the conditions. The beaches in WA are known for its soft sand, hence why we always go down to 15 in summer.

[JCOJ]

Cooper Tyres also have a little booklet which is like the tyre pressure Bible - very informative and I have been using the guide for as long as I have been 4wdriving and have never had a puncture (touch wood).

You can get it here: http://www.coopertires.com.au/index.php?page=free-info-pack

[nuozzie]

Hi I saw that last night and sent off for it you must be a mind reader lol.
Paul