275/45R20 -> 15 PSI - Dune drving

[ontheway]

All,

(I am searching but seeking wise input)

I stumbled across a Stockton beach tag along tour this afternoon and am thinking about joining their tour in the next few days.

The only concern from the operator (fair enough, we don't want to hold the rest of the tour up) is that they run 15 PSI as standard for the dunes and low profile tyres are issue.

I run 275/45s in lieu of the really low profile 275/40s that were original (and frankly were too low profile). Tyres are Conti LX Sport so not LT etc. OEM rims.

Am I kidding myself running 15 PSI with my setup in the short term? The operator slightly concerned about bubbling etc. I'm not that concerned about damage provided they get us home.

[Arch]

Yes tyre pressure and tyre volume (ie floatation) is 90% of successful sand driving. Low pressures with high volume are desirable hence the operators recommendation.

Anyhow, I'm 255 50r19 on my RRS at 20psi (warm tyre temps) down here on Tas beaches (including west coast) with no issues on goodyear eagle f1 road rubber. Beach sand varies a fair bit and Stockton inst any different but I suggest you start there and adjust if required.

I assume you are taking your own compressor?

[Slunnie]

Stockton is some of the softest sand you will drive on. The pressure depends on a lot of things. Even with the same vehicle, I run my Simex, MTR’s and Pirelli ATRs at very different pressures in the sand. I really dont think you would run your tyres at 15psi without putting the rim on the ground. But they’re a nice broad tyre for the sand also which will give floatation. I suspect without advice from others who have done it, you might be finding out on the day, but the Disco2’s on 255/55-18 that Ive seen haven’t been very good on the sand.

[josh.huber]

I did the sand mastery course with Gordon back in the day, he said the LR rims have a really good bead and you wouldn't pop them. I've been down to 10psi without issue to get out.
But normally around 15 from memory.
The first time I went on the beach I thought that the tyre pressure would do nothing with such a small sidewall and joined the 40psi club.
I've got standard 255/50r20's on mine.

Should be good fun

[Dagilmo]

I did sand with Gordon also. My recollection was he had all cars (some with 19" and 20") in the group at 15 psi. I have 285/60/18 which I use generally on sand and (run at 15 as my standard) but on one trip I had the 20"s and ran them at 15 psi at Preston Beach (not a difficult beach generally- though have seen plenty get stuck if they don't have correct pressures) and had no trouble.

[Eric SDV6SE]

Just drop to the pressure that gives you flotation keep the rest up your sleeve. Start at 20psi. At 275 width, should have enough area to get up on the sand.

[ontheway]

I assume you are taking your own compressor?

(yes, compressor, two sets of Maxtrax, shovel, strap and IID tool)

Thanks all, very helpful. I also found a glossy reference on the landrover.com website specifying 15 PSI minimum in extremely general terms. (https://www.landrover.com/ownership/4x4-off-road-driving-tips/off-road/sand-driving.html)

Went out yesterday with Bruce from 4WD Tag-Along tours (https://4wdtour.com.au/) to the restricted area dunes at the north end of Stockton beach.

No problem at all @ 15 PSI on the 275/45R20. Up and over the dunes - i was conscious of the lack of rim protection but didn't feel like they were at risk. Sand was indeed soft.

I think that I could well have kept the pressure higher (starting at 20 as suggested) but we were playing with the standard rules, which worked well on the day. I got somewhat in tune with the car but can see how practice helps. L320 low range 1st is much lower than a land cruiser. I quite liked the paddle shifters - ironically, haven't ever used them on road.

it was an easy relaxed 3 hour late afternoon outing and intro to dune driving in the restricted area - not a technical course - and sand boarding. Young fella loved it. Highly recommended.

[josh.huber]

(yes, compressor, two sets of Maxtrax, shovel, strap and IID tool)

Thanks all, very helpful. I also found a glossy reference on the landrover.com website specifying 15 PSI minimum in extremely general terms. (https://www.landrover.com/ownership/4x4-off-road-driving-tips/off-road/sand-driving.html)

Went out yesterday with Bruce from 4WD Tag-Along tours (https://4wdtour.com.au/) to the restricted area dunes at the north end of Stockton beach.

No problem at all @ 15 PSI on the 275/45R20. Up and over the dunes - i was conscious of the lack of rim protection but didn't feel like they were at risk. Sand was indeed soft.

I think that I could well have kept the pressure higher (starting at 20 as suggested) but we were playing with the standard rules, which worked well on the day. I got somewhat in tune with the car but can see how practice helps. L320 low range 1st is much lower than a land cruiser. I quite liked the paddle shifters - ironically, haven't ever used them on road.

it was an easy relaxed 3 hour late afternoon outing and intro to dune driving in the restricted area - not a technical course - and sand boarding. Young fella loved it. Highly recommended.

We are here today and I went straight to 15 on 255/55R20, it's a bit soft. But the car eats it.. What I did notice when setting up the shade etc was moving around with sand mode and the ultimate 9 throttle on 2 was to agro. I've hidden the controller for the throttle controller so I put it back in normal mode. Was much better for slow manovering

[Redtail]

I did sand with Gordon also. My recollection was he had all cars (some with 19" and 20") in the group at 15 psi. I have 285/60/18 which I use generally on sand and (run at 15 as my standard) but on one trip I had the 20"s and ran them at 15 psi at Preston Beach (not a difficult beach generally- though have seen plenty get stuck if they don't have correct pressures) and had no trouble.

Me three!

I would regularly drive Preston, White Hills and beaches further south at 15psi on my factory 19's with Pirelli ATR's. No problem at all.
And being genuine LR rims, bead seal is superbly strong. Very little chance of peeling a rubber off.

[Eric SDV6SE]

Don't think I've ever gone as low as 15 psi on 19" rims with 50 profile tyres. Last run from Preston Beach to Tim's thicket was at 18psi with no trouble at all. On HT by the way.

[Redtail]

Don't think I've ever gone as low as 15 psi on 19" rims with 50 profile tyres. Last run from Preston Beach to Tim's thicket was at 18psi with no trouble at all. On HT by the way.
I could say I've gone to 10psi at Bellanger Beach, Walpole, to get me out of the deep stuff on one occasion. But I thought it'd sound like bragging. [bigwhistle]

To the OP - These things will go anywhere. Ignore the "conventional" wisdom of old-school fourbies, and have a blast!

[DiscoJeffster]

Don't think I've ever gone as low as 15 psi on 19" rims with 50 profile tyres. Last run from Preston Beach to Tim's thicket was at 18psi with no trouble at all. On HT by the way.

55 profile but who’s counting. I use 15 front 18 rear as a baseline. I’ve gone to 8psi both ends to get out of a bad beach bogging and they were fine (on factory rims at least).