Average Tyre Pressure

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nqgu
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Re: Average Tyre Pressure

Unread post by nqgu » February 27th, 2011, 8:03 am

altho using the same footprint length under all load conditions isn't such a good thing!
Not true.
Dealing with the various loads is precisely what the footprint method is designed to do, as well as dealing with various tyre construction types, which a pressure value alone does not do.

Inflation pressure and load go hand in hand. One changes the inflation pressure to deal with the load, according to the specification of the tyre manufacturer.

Tyre manufacturers design a tyre to provide a particular footprint when inflated to the correct pressure for the load. When one uses the footprint method, one is in fact arriving at the correct pressure for the load by observing actual changes to the tyre footprint.

The only thing the tyre footprint method doesn't itself take account of is the heat generated by the speed of travel. This requires a second rule of thumb- ie. 80% inflated means 80% of maximum speed. <85kph. 50% inflated <50 kph. The 4psi rule does take in to account the heat generated by speed.
There have been some changes.
I used to live in NQ, I now live in Sydney and that is the minor change.

Pog
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Re: Average Tyre Pressure

Unread post by Pog » February 27th, 2011, 1:17 pm

UsIng the 4psi rule, mine are set to 29psi front/27psi rear. 2002 Hilux dual-cab

I've experimented a lot with pressures, and these by far give me the best wear, ride comfort and handling.

O-D
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Re: Average Tyre Pressure

Unread post by O-D » March 12th, 2011, 4:03 pm

I take my 31"x10.5" R15 All/Terrains down to 12PSI on the sand (soft sand dunes), 14PSI on the rougher off-road tracks and 20-25PSI on dirt/gravel roads.

I'm running them at 35PSI on the road but haven't worked out the best tyre pressure for this yet???

tough105
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Re: Average Tyre Pressure

Unread post by tough105 » May 4th, 2011, 3:27 pm

I am a driver for a tour guide company that amoungst other things runs trips to fraser/moreton and when we use toyota troopcarriers to move people around we tend to keep the tyres at 45psi and that will work fine 99% of the time and the other 1% I just tell my passengers to get out and push. However, on my own car which is a 2001 hzj105 I run 40psi on the road and about 20psi when i take it on the beach.

OzDrew70
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Re: Average Tyre Pressure

Unread post by OzDrew70 » May 16th, 2011, 9:13 pm

Ahh...Beach Driving.

Let me share a personal story with you all.

My family and I were travelling around Oz last year and always looking for adventure (well I certainly was) and I/we decided to continue on after visiting talia caves (turn off Flinders Hwy onto Talia Caves Rd just nth of Talia or sth of Port Kenny).

Anyway...Lake Newland Conservation Park sits on the Great Australian Bight and from Talia to Elliston is a maze of sand dunes. With the truck fully loaded I decided to let my tyres (265/70 R16 Coopers AT) down to about 22psi and continued through without any problems.

The driving was great and the scenery even better, every now and then popping up high on a dune and getting a view of the Great Southern Ocean. The tracks were now starting to become a track and 'THE track' started to fade into six foot high scrub with sand as its nutrient.

The only option(s) were small openings heading onto the beach, so doing what any educated, experienced 4WDer would do was to stop get out and check out its driveability. Seemed ok, so I dropped the tyre pressures down to 18psi.

This is where the adventure started and the pucker clenched up REAL tight. The second we drove onto the beach with limited momentum given the opening to the beach, the 4B sank to its belly. No worries, grab the maxtrax and let the tyres down to 16psi and head towards the harder packed sand. This is when my pucker could puck no tighter. It ain't packed sand, it's more like quick sand.

With the Great Southern Ocean bearing down on us, I quickly looked up tide times. Hmmm...No mobile service. Excellent. What is the tide doing coming in or going out? Who cares! Let's just get outta here. With the tyres now down to 10psi and the maxtrax working overtime (and just short of digging the spare tyre in), I drove back up to the dry and slightly more compact sand well above the high tide mark.

With the vehicle high and dry, we had some decisions to make, either turn around and make the journey all the way back...Or, continue on along the beach to an exit marked on the map as Walkers Rock where there was a campground.

After attempting to drive in both 4x4 high and 4x4 low (all gears), I let the tyres down 2 more psi to 8. With plenty of right boot, this would test the mighty Navara out to its limits. Fully loaded, soft sand and flat stick in whatever gear would keep us moving for the next (i think) 20+km makes all your senses come alive. Especially driving one a beach along the Great Australian Bight. I'm just glad the bloody thing was pretty straight.

We eventually made it to Walker Rock and I was going to suggest we set up camp but my conscience got the better of me and I decided to offer the wife and tin lids a cabin in Elliston. Best decision ever made (at the time).

The moral of this story is that no matter what tyres you have on, pressures are everything and recovery gear is essential (especially travelling solo) and remember boys and girls...

TAKE THE FLINDERS HWY from Streak Bay to Elliston, cause it's the same distance, only 5 hours quicker.

OzDrew70
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Re: Average Tyre Pressure

Unread post by OzDrew70 » May 17th, 2011, 6:38 pm

Here's a picture of what happens when you get lazy and don't let your tyres down. This was on the Gibb River Rd from El Questro to Kunanurra, part dirt track, part bitumen to the main road between Wyndham and Kunanurra which is all bitumen.
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Mud Salami
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Re:

Unread post by Mud Salami » June 16th, 2011, 11:44 pm

matt.s.FC wrote:I've never done anything with tyre pressures.

onroad - 40psi
offroad - 40psi
same.... i just read the side of the tyre!!
except for beach, then i drop it down, but again depending on the type of sand... soft fluffy stuff gets the pressures lower then the more compacted stuff.

Pog
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Re: Re:

Unread post by Pog » June 17th, 2011, 12:35 pm

I hope you're not using the Max. Pressure on the tyre. Because that's the only pressure that's ever stated there!

Mud Salami
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Re: Re:

Unread post by Mud Salami » June 20th, 2011, 12:39 pm

hmmm... true.... food for thought....

Mud Salami
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Re: Average Tyre Pressure

Unread post by Mud Salami » June 20th, 2011, 11:04 pm

Had a look... Now I know why I put 40psi... Max pressure is listed as 50psi...

Zeropoints
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Re: Average Tyre Pressure

Unread post by Zeropoints » August 17th, 2011, 12:17 am

Have there been enough info gathered to draw any conclusions yet? Heres my info. Ranger with original rims, original Bridgestone Dualer A/T 245/70R16 tyres. Sticker on vehicle says 30psi F and R unladen, 30psi F and 35psi R laden. Unladen pressures give an increase of 4psi after 3.5 hours at 110kph. On gravel and firm offroad, 20psi F and R. On soft beach and long uphill, like getting off Bornholm Beach, 8-10 psi makes it easier and less of a drama.

DamoBro
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Re: Average Tyre Pressure

Unread post by DamoBro » August 19th, 2011, 10:12 am

I have a 60 series crusier with 33' bighorns.

Road
30 - 35psi

Bush
20 - 25psi

Beach
I do alot of camping on the beach. The beach we go is notoriously soft. I run anywhere between 8 - 12psi. Usually start on 12, and work my way down. Was trying to climb some massive dune once and had them on 5... one time thing.

My mate has a feroza, he drops anywhere between 3 and 8 straight up. Stuff that haha.

prawns
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Re: Average Tyre Pressure

Unread post by prawns » August 19th, 2011, 10:58 am

my 93 pajero reckons 26psi front and 29psi rear (tyre placard) but i run 35psi right round on the road normally (steering feels more responsive but its a harsher ride)

26psi seems rather low for normal use?
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cac
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Re: Average Tyre Pressure

Unread post by cac » September 3rd, 2011, 9:36 am

Have there been enough info gathered to draw any conclusions yet? Heres my info. Ranger with original rims, original Bridgestone Dualer A/T 245/70R16 tyres. Sticker on vehicle says 30psi F and R unladen, 30psi F and 35psi R laden. Unladen pressures give an increase of 4psi after 3.5 hours at 110kph. On gravel and firm offroad, 20psi F and R. On soft beach and long uphill, like getting off Bornholm Beach, 8-10 psi makes it easier and less of a drama.
I edited my original post on this thread a while back, with the following comment....
EDIT: did a quick re read of this thread, just to see what kind of pressures different people are running in different conditions....the majority of us prefer the tyres below 20psi for sand driving, as well as most low range stuff, and for general dirt road stuff, either the same as road pressures or 25psi plus...20-25psi seems like a good middle ground for general high range usage....

nothing wrong with differing from the pressures listed above either....its a matter of finding what works best for your rig/tyre combo....
to add to that, I would suggest 16psi or below for soft sand or more extreme low range stuff....

as stated a few times in this and other threads though....if you aren't getting enough traction or floatation at whatever pressures you are running, don't be afraid to drop them a bit more to get out of trouble....just remember you have an increased chance of rolling the tyre off the rim the lower you go though....I'd be quite reluctant to go to single digit pressures without beadlocks unless absolutely necessary....like when in the situation OzDrew found himself in.....
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IGGIE
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Re: Average Tyre Pressure

Unread post by IGGIE » March 6th, 2012, 9:41 pm

My Troopy 75 series with Cooper 33inch
40 psi Black top
30 psi corrugation
22 psi Cravel
18 psi or less on sand
I have 3 sets of Staun Deflaters set at 30psi, 22 psi & 18 psi saves time, but pump them up again when you hit the hard top.
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