Dirts roads and Fiat Ducato

Steel Dog · Veteran Member

Dirts roads and Fiat Ducato

bgt · Guru

Thanks Steel Dog. I won't get into a debate about the 'motorhome' build quality. I was more interested in the 'Fiat' aspect. And as full disclosure we have a Horizon campervan.

Just as an aside. Back in the 1990's we had a higher end 35ft motorhome in the USA. We drove to Alaska and back. Anyone who thinks Australian roads are the roughest in the world needs to drive through Canada and Alaska. Anyway we discover many squeaks and rattles. While we drove the wife went around the motorhome with a pack of stick note pad. (Not a safe practice). She put a bright yellow sticky note on every rattle. Each night I attended to those rattles. By the end of the trip we had the tightest motor home in the USA!!!

Every motorhome has rattles.

PetenSue · Veteran Member

Whenarewethere wrote:
Have you tried letting tyres down, makes a massive difference on dirt roads.

Yeah I cant get this letting the tyres down. I have never deflated my tyres and I m thinking I do a lot more remote miles than you. Even the ladies from the stations I work on dont air up or down when they go shopping. This letting the tyres down(apart from soft sand country) comes from watching too much tv. Im driving on **** gravel or dirt roads very very regularly and never let my tyres down. Been years since I had a flat tyre. Then again Im not driving a motor home. Regards Pete

msg · Guru

Pete, I'm a bit like you. I don't get the letting the tyres down thing either. I also spend more time on unsealed roads than on bitumen.

My thoughts are generally, the roads are full of very sharp rocks and I can't see how a lower pressure would be beneficial.

Touch wood, and I have been driving my Ford Transit for 12yrs now and no punctures. I think the secret might be in the light truck tyres.

Aus-Kiwi · Guru

Does give better grip and ride .Depends on type of tyre combo ? High profile tyres can run lower air pressure to give wider contact patch . Also softer ride . Must travel slower . In my case with 19.5 X 225 the psi recommended for weight is 90 Lb . It will run 60 easy . Any lower the tyre temps increase .

Jaahn · Guru

Hi smile

Regarding reducing the tire pressures. My opinion. You can go around with the tires pumped up to the max if you wish and if you are happy to do that OK. Better than never putting any air in them for sure. Some vehicles do ride better than others so that has some bearing on it as well as the tires fitted. wink

But letting the tires down is an option in the "toolbox" to use as you wish. I do it if necessary as my minibus MH is crazy on corrugations even very slow. But you do need a good compressor so you can pump them up in a shortish time or you get sick of it quickly. But there are plenty of 4WD types that will do it OK just do not get those small cheap things as they are just crap. You cannot wait till you see a service station 'out there'. Who knows what pressure is best. Suck it and see is the answer ! aww

Jaahn

-- Edited by Jaahn on Wednesday 29th of January 2020 01:47:09 PM

Peter_n_Margaret · Guru

"Who knows what pressure is best. Suck it and see is the answer !"
The correct answer is the pressure that does not cause the tyre to overheat due to the extra flexing.
Moderate tyre pressures will require significant speed reductions to ensure the tyres do not overheat.
Tyre overheating will cause rapid delamination and failure.

Appropriate pressure reduction combined with appropriate speed reduction will not only improve comfort and reduce vehicle damage but will also reduce tyre damage by rocks and the like, this is why most military vehicles are fitted with facilities to adjust tyre pressures on the run.

In soft conditions, the reduction of tyre pressures may be the ONLY way to maintain progress without bogging.

Cheers,

Peter

Whenarewethere · Guru

Letting down tyres depends have much you value your vehicle & your comfort.

Two compressors under driver's seat, one compressor & 4L air tank in boot under spare wheel. Moisture trap in boot. A couple of oil coolers used as an after cooler. Everything removable for draining.

Enough air to clean the car with or without water (water at 0.5L/minute)

It takes us longer to take off & replace the TPMS than pump up the tyres.

If you have a slow compressor I can see exactly why one couldn't be bothered waiting forever to pump up tyres.

Whenarewethere · Guru

Peter_n_Margaret wrote:
"Who knows what pressure is best. Suck it and see is the answer !"
The correct answer is the pressure that does not cause the tyre to overheat due to the extra flexing.
Moderate tyre pressures will require significant speed reductions to ensure the tyres do not overheat.
Tyre overheating will cause rapid delamination and failure.
Appropriate pressure reduction combined with appropriate speed reduction will not only improve comfort and reduce vehicle damage but will also reduce tyre damage by rocks and the like, this is why most military vehicles are fitted with facilities to adjust tyre pressures on the run.
In soft conditions, the reduction of tyre pressures may be the ONLY way to maintain progress without bogging.
Cheers,
Peter

We have TPMS & can see the change in tyre pressure. Probably a greater change on the sunny side of the car compared to the shadow side.

If we let down our tyres from 35psi to 24pdi, once the tyres have warmed up at either pressure it is about the same increase. We also drive slower on corrugated roads. If we have to drive on sealed roads a bit with lower pressure we also go slower.

We also stop a bit more often to give the shocks & us a break on corrugated roads.

Whenarewethere · Guru

Peter_n_Margaret wrote:
In soft conditions, the reduction of tyre pressures may be the ONLY way to maintain progress without bogging.
Cheers,
Peter

Or getting out of a bog.

Have a cup of tea............. Let tyres down!

PetenSue · Veteran Member

When was the last time youve ever seen or heard of someone who lives and works out in these remote areas letting tyres down or pumping them up just because the road changes from bitumen to gravel ? The ladies from the stations sure dont whenever they go to town shopping. I sure dont when I travel up to 400 kms on all sorts of rough roads and tracks to go to a job. I value my vehicle thanks. I have a 3 cylinder electric start Honda powered air compressor bolted to my ute. Its used every day to blowout the dozers radiator so pumping tyres up fast is no problem. We use the same principle when we travel around in our caravan. And yes I do agree travelling in loose sand is totally different. I let my tyres down then. Regards Pete

Peter_n_Margaret · Guru

In my experience, they start with them at lower pressures and leave them there.
Cheers,
Peter

Whenarewethere · Guru

At the entrance of Purnululu NP the sign says reduce tyre pressure by 10psi from normal highway pressure.

When we were entering & exiting we noticed about 10% of the vehicles adjusted their tyres. Also about the same percentage we have noticed on other similar roads including Gibb River Road & the public road north out of Karijini NP through Millstream NP.

Top end of the Oodnadatta Track 100% let their tyres down when we were there.

100% let tyres down at Francois Peron NP, sign said tyres to be at 20psi.

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PetenSue · Veteran Member

Well you do it your way. I will do it my way. We are very used to being treated like dumb arses by the tourists any way. Regards Pete

Warren-Pat_01 · Guru

Bruce,
I've driven over all sorts of roads but not in a motorhome. If you have good tyres with plenty of tread & regulate your tyre pressures (ask an expert tyre fitter) & drive to conditions, mostly you won't have any troubles. Don't worry about any yahoos that might pass you - you'll probably see them broken down further up the road.

Check your proposed route with the BOM, a council (they should be able to tell you when the road was graded), a motoring club or a police station. Bear in mind that conditions could change quickly.

If you have any apprehension about your vehicle, ask Pedders or Fulcrum Suspension how they could improve/upgrade it.

Carry suitable spares but don't go overboard as excess weight can cause more troubles.

Warren-Pat_01 · Guru

I'm not having a "dig" but for those members who don't believe in letting their tyres down (I was there a few vehicles ago, too), there have been interesting tests in some of the 4X4 magazines showing tyres going over "extreme" objects & seeing how long the tyres lasted at various pressures. I think the pressures you use must depend on the surface of the road at the time.

When we went to "The Tip" in 1992 in our MQ Patrol, I ran radial 7.50x16 tyres qt 50psi (on both the Developmental Road & the original Track(?)! Driving across the Jardine at full wheel immersion depth (you could so it then), I took them down to 32psi. The car was loaded with a roof rack on top.

Since I bought my last Patrol, I kept LT rated Bridgestone 697 tyres on the car & had no troubles at all but I always had good tread. I ran 40psi in it around town, 43 on highways & towing & down to 36 on roads like the Birdsville (Highway) - with a Jayco camper on the back. I blew a tyre on our van last Easter on the Flinders Highway - I put that down to having the pressure a "bit too high".

PetenSue · Veteran Member

So spitting some iconic road names makes you feel like you know what youre talking about. Gibb river road. 3 times thanks. Reminds of the yaraka road down through budgerigar Trinidad through to the bitumen at thylungra, countless times. Sharp stones and corrugated. Oodnadatta track. Several times. Reminds me of the road between aramac and Ilfracombe. Countless times. Bit of gravel mostly dirt. As I said before. Know it all tourists who treat locals like dumb arses.

Whenarewethere · Guru

We have a comfortable ride, 20psi to 35psi 35 seconds a corner, easy!

landy · Guru

Its been 10 years since I was last there but the tyres fitters and staff at the Pink road House Oodnadatta were insistent that tyres pressures should be lowered in their environment. take it for what it's worth.
Landy

Whenarewethere · Guru

A comment from Outbackjoe.

'I had a chat to an owner of a 4WD tour business in the Kimblery of WA. He runs trucks with passenger cabins fitted to the tray up and down the Gibb River Road showing tourists around. What pressure does he use on his fleet of trucks for this bumpy and corrugated road? About half highway pressure. For the trucks highway pressure is about 90psi and he runs about 45psi. He does it to reduce risk of tyre damage, reduce suspension maintenance and improve ride quality for passengers. If an owner of a fleet of tucks is reducing pressure on dirt then that's pretty good evidence that reduced pressure is of benefit.'

Peter_n_Margaret · Guru

I run Michelin highway tyres on the OKA.
Michelin publish load/pressure/speed charts for off highway use for those tyres.
I reckon they know something about tyres.
Cheers,
Peter

bgt · Guru

FWIW on the weekend we did some dirt/gravel roads. One 3k section had a flood way followed by hard curve and an approx 12-14% climb on loose gravel for about a k. So no run up. No issues what so ever. No wheel slip. (Note it's the road up to our daughters house so we know the road and the grade of the hill).

Note that we have a Fiat Ducato campervan not a motorhome. It also has the Fiat Traction+ option.

More confident on gravel now!!!