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Unread 26th November 2017, 12:52 AM
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Thumbs up Tyre/Tire Pressures. What do you run?

In an effort to try and find out what's recommended, I've started this one thread fits all thread about tyre pressures.

2 days ago I had some Dueler A/Ts fitted, 215R65/16C.
Bridgestone put them on at 38psi (that's whata it was when I got the car home, so would have been warm.
Went for a little drive to see how they felt yesterday. Noticeably more feel on the road which was to be expected.
Got to the start of the dirt, deflated them down to 30psi. Made the corrugations quite bearable.
When I got to the rough stuff, I deflated to 25psi.
Very smooth on the whole.

Problem is, I've really got no idea what I should be running them at.
I've read in various threads that people go down to 22PSI off road, below 20 for sand.
For on road use, discussion seems to be fairly even between what the tyre dealers inflate to (high 30s) and what the vehicle manufacturer recommends (about 28-30 on the SG)

Currently I've inflated back to 35 when warm for road use to spllt the difference but would appreciate input.

What do you run your pressures at?
a format of:
Tyre
Tyre Use | Pressure
would make things nice and clear for readers

So to start..

Bridgestone Dueler A/T 215/65R16C
Road | 35psi
Dirt | 30psi
Offroad | 25psi
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Unread 26th November 2017, 01:08 AM
MiddleAgeSubie MiddleAgeSubie is offline
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BFG TA KO2:

Road: 39 cold
Dirt road: 28 hot
4x4 trail: 21 hot or 18 hot, if anticipating more traction challenges
sand: as needed

Geolander ATS or COntinental AT or any other non-LT tire:
Paved road: 35 (ATS), 32/30 (Conti AT)
Dirt road: see paved road
4x4 trail: 28 (ATS), see paved road (if the Conti AT ever go on 4x4 trail).
sand: as needed

There is no point airing down from 35 to 30 for dirt. You could go 35 for around town or long road trips but once you start your unpaved adventure, just stay at the door pressures on and off road. There is absolutely no appreciable traction benefit at 30 vs 35 and ride quality should not be an issue with a Subaru wearing P-metric tires.

If you are short on traction, then you will want lower pressures, specifically 20 and lower. Subaru AWD is pretty poor in rock so that is where lower pressures come into play (sand aside). In turn, this requires strong sidewalls, hence 3-ply sidewall, LT tires. But if you only deal with generic rock on dirt roads, then the LT tires are an annoying overkill. Having to air down for any dirt road to keep the ride smooth is, in itself, a good enough reason for me to use the KO2s only for trips that involve actual 4x4 trails.
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Unread 26th November 2017, 01:35 AM
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Quote:
Originally Posted by MiddleAgeSubie View Post
BFG TA KO2:

There is no point airing down from 35 to 30 for dirt. You could go 35 for around town or long road trips but once you start your unpaved adventure, just stay at the door pressures on and off road. There is absolutely no appreciable traction benefit at 30 vs 35 and ride quality should not be an issue with a Subaru wearing P-metric tires.
Thanks for the info, The tyres were at 38 originally. Dropping them to 30 certainly seemed to take the sting out of the corrugations compared to running a road tyre, but then I hadn't really tried the Duelers on corrugations before, so it could be that they'd be as comfortable at full pressure.

Door pressure for the SG is apparently 29 at all times on the front, 28 (unladen) to 40 (towing) on the rear

I guess my biggest concern is getting a decent life out of the tyre without uneven wear due to over/underinflation.

It's so confusing.
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Unread 26th November 2017, 01:51 AM
MiddleAgeSubie MiddleAgeSubie is offline
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If they are P-metric, they should wear well at door pressures or a bit higher. Use IR termometer to see if center heats up as much as the edges.

You will NOT get good life from any tires actually used in harsh terrain. It comes with the territory. But forum members from Australia will give you better idea about what you can expect.
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Unread 26th November 2017, 02:00 AM
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Quote:
Originally Posted by MiddleAgeSubie View Post
If they are P-metric, they should wear well at door pressures or a bit higher. Use IR termometer to see if center heats up as much as the edges.
Hmm.. now I've got to get an IR thermometer!

Quote:
You will NOT get good life from any tires actually used in harsh terrain. It comes with the territory.
I learnt a long time ago that good (or decent) is a very relative thing.
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Unread 26th November 2017, 02:46 AM
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Haha. So it is!
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Unread 26th November 2017, 06:30 PM
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Good idea for a thread.

Geolander G012 205/75/15
Kumho Road Venture KL71 muddy 215/75/15
Road
34psi
Dirt
25psi
4wd tracks
20psi
Sand/difficult tracks 16psi
Soft sand 12psi

You can go down to 8psi to get out of a very soft section of sand but air back up to 12psi when you can.
Be careful turning on 12psi, it's easy to roll a bead
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Unread 26th November 2017, 07:10 PM
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Quote:
Originally Posted by Ben Up North View Post
Hmm.. now I've got to get an IR thermometer!
I've got one; it's my palm and "I Reckon" it's about right!

BFG TA KO AT 21575R15

My pressure depends on loaded / unloaded / road conditions / on-road / off-road / mud / sand / rocky / etc but in general:

Road 34-36 psi
Dirt
28-32 psi
4wd tracks
22-25psi
Sand/difficult tracks 18psi initially
Soft sand 14psi (drop to 10 if necessary)

Good idea Ben, I've stuck the thread
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Unread 3rd December 2017, 05:18 AM
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Road Used to always run 34, now 38 on advice from tyre dealer and no problems re being too harsh.
Dirt
To date, haven't gone on extended dirt tracks so I just leave pressure as is and never had a problem.
4wd tracks
I will have to let you know! My off-roading of any significance has all been on sand!
Sand I've always run at 18psi and only went down to 10psa at Ngkala Rocks at Fraser Island in very soft sand. I might have made it at a higher pressure so maybe I will try again and see another time! So, other than dropping to 10psi at Ngkala Rocks I have done Fraser, Moreton and North Stradbroke Island at 18psi without problem so feel confident that this is a good starting point.
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