Member Since: 13 Sep 2007
Location: Melbourne
Posts: 229
Why do we use lower tyre pressures off road?
In Australia, it seems that religiously people drop pressures when going off road. It may be my imagination, but this does not seem to be a well supported process by those on this site around the world. Am I just imagining things?
It does not seem to matter what sort of terrain, here - off road = low pressures. (I think many go down to 20 - 22 PSI) Lots of Bagging out of the tyres. I pressume this is done to ensure maximum contact possible between tyre and ground.
My question (yep - finally got round to it) - What tyre pressures for off road?
I am running 18s, in an AT.<*(((<<
7th Dec 2008 9:05 am
CFB
Member Since: 02 Dec 2005
Location: Bradford, West Yorkshire
Posts: 6100
I never change pressures for mud, rock etc. Seems that sand requires it to stop tyres digging down but never needed it for any other off road situation2020 BMW X1 18d XDrive X-Line Auto
As CFB said - on sand it's better with low pressures, but I've never let them down for other surfaces, with no problems. Especially rocky ground, I'd prefer enough pressure to stop the rims getting damaged. On road tyres (Scorpions) with about 4mm left on each, I managed fine yesterday on a very slippery Salisbury Plain:
Click image to enlarge
Previously:
2005 D3 2.7 TDV6 S
1984 90 2.25 Petrol CSW
1992 90 200TDi Hard Top
1995 Discovery ES 300TDi
2003 90 TD5 Truck Cab
7th Dec 2008 10:55 am
caverD3
Member Since: 02 Jul 2006
Location: Oberon, NSW
Posts: 6922
I have always lowered pressures for unsealed and off road but I have mine slightly higher than LR spec for black top.
On unsealed roads slightly lower pressures give a softer ride and a bit more bite.
Slightly lower pressures on rock will help the tyre 'form' to the surface rather than sitting on high points. Not too low so sidewalls aren't exposed.
I forgot to do this rock crawling once and the D3 still held its own against a lifted Pootrol.
Much lower is required on sand where the sidewalls will be vulnerable.“There are only three sports: bullfighting, motor racing, and mountaineering; all the rest are merely gamesâ€
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7th Dec 2008 11:14 am
Jonty
Member Since: 13 Oct 2007
Location: On the beach
Posts: 417
Lowering pressure increases tyre foot print = more traction. Also helps the tyre mold itself around rocks and stones when rock crawling.
It makes a huge difference on sand and rock crawling but also helps in mud.
7th Dec 2008 2:13 pm
Tassierob
Member Since: 16 Nov 2008
Location: Hobart
Posts: 73
Do a wet rocky section of trail with the tires at road pressure and watch how hard the traction control works, then let the tires down to say 25PSI and drive the same trail again. You will be surprised at how much less work the electronics have to do. You will also find the ride is far more compliant as the tires don't want to bounce off the rocks when you hit them.
There is also an interesting side benefit...less wheel spin means less track damage...which hopefully means the people who want to see them all closed will have less reasons to attack us. Our children will then be able to enjoy driving in the bush rather than having to walk everywhere our spending half their life filling our forms and getting keys to lock gates Life is short...get it dirty...as often as you can.
TDV6 SE, ARB Bar, Warn 9000lb winch,Kamar rear bar/tyre carrier/jerry can holder, IBS duel battery system,Safari Snorkel, Black Widow draw system, Cargo Barrier, Lightforce 240XGT driving lights, Hemma GPS, Tyre Dog tyre monitor system, Mickey Thompson MTZ 265/70/17, Off Roving rock sliders, Hannibal Rooftop Tent, Open Sky awning.
7th Dec 2008 11:21 pm
AndrewS Tarquin of the Desert
Member Since: 06 May 2005
Location: Y...... because I can
Posts: 10442
Lower pressure also helps 'flick' mud out of the tread as the tyre flexes as it rotates thus clearing the tread In the Beginning there was nothing, which exploded.
7th Dec 2008 11:25 pm
norto
Member Since: 10 Apr 2006
Location: batemans bay
Posts: 1605
4x4 Australia ran a landcruiser tyre over a bolt protruding
from a piece of flat steel.
With recommended tyre pressures the tyre got a puncture every few times
it ran over the bolt.
It took something like 20 passes to puncture the tyre with 20 psi in it.
The tyre blokes in the outback reckon the way to stop punctures and chipping
on the Oodnadatta and Birdsville tracks is to let the pressures downPete
8th Dec 2008 1:26 am
Desert Traveller
Member Since: 06 Aug 2006
Location: The Gabba - QLD
Posts: 420
As others have commented. The more you let out the further you get with less damage to the tyres and the environment. I was slack on the weekend with my MTRs and didn't drop the pressure for one slippery hill and absolutely struggled where normally (with lowered pressures) it was a walk in the park.
Why do comp vehicles have bead lockers? So that they run some very low pressures.
As an offroad instructor, tyre pressures are at the top of the list for traction assistance.06 TDV6 SE with many LR and after-market extras. Used only on weekends and trips out west.
Audi TT Roadster (Daily and around town drive)
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Previously 01 TD5 and 94 TDI
8th Dec 2008 2:35 am
Getafix
Member Since: 13 Sep 2007
Location: Melbourne
Posts: 229
Thanks for all the replys. I remain interested in the fact that in some parts of the world the airing down is consistant, in other regions, not so much. For such a basic component of off roading, I will just say, interesting.
Going off road this weekend, I will try 22-24 psi, and see how I go.<*(((<<
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