Suspension Tyre Pressure Cold/Hot

[Drover]

Go by the information on the tyre not all tyres have the same load or pressure ratings, the info on the plate may relate to a totaly differn't tyre, the "Don't inflate beyond ##psi " is for when fitting the tyre, when blowing it onto the rim.
Sounds about right I think but this pressure of course is a good starting point you may want to go higher or lower, depending on how things ride. pare was at a good pressure though.

I adapted it from info on my all time favourite Caravan Site............. https://caravanchronicles.com/guides/

Full of great info and very handy to check things....

 

[Dean Anderson]

I have no idea what I'm talking about....but......I believe there are a lot of variables involved in what we are trying to make simple. Not all tyres are the same....Not all manufacturers supply products of the same quality, and hence the variables change, even if they theoretically conform to a specification at the time of manufacture, some manufacturers strive to increase quality and reputation, some don't. Manufacturers that have been around for a long time have probably avoided an unsustainable level of law suites.

I believe there are two options after you follow the vehicle manufacturers advise (on the compliance plate) with respect to tyre selection. Those being:

1 Trust the tyre manufacturers advise, and if they don't give advise with respect to driving in the conditions that you are driving in, choose a brand that does.

2 Monitor your tyre pressures if you are doing things without the manufacturers advise, and stay within the pressures stated. This of course involves installing a monitoring device. I haven't cause I don't do a lot of off-bitumen driving, if I did I would. In reality I believe it's the only real way of ensuring your pressures suit the road surface and installed tyres. Wrong pressure and your tyre ends up like the pic above.

In the last 20 years I have only had three tyre problems. A batten screw, a valve stem, and a blowout (pressure related) as pictured above.

My presumed causes of the above are below:

Batten Screw: A remote tyre service increasing business on gravel roads.

Valve stem: Old age

Blowout: Wrong tyre pressure (may have been caused by a leak or ignorance).

 

[mikerezny]

Batten Screw: A remote tyre service increasing business on gravel roads.

Hi @Dean Anderson,
at the expense of being accused of wandering off-topic.....
This brought back an old memory.
Many, many years ago, miles of the Bruce Highway was re-tarred just before Maryborough, Qld. You know the old days, spray hot bitumen from a truck, cover it with gravel, roll it down, let it settle, and sweep it off. Then put lots of signs up for people to slow down to avoid throwing up heaps of loose stones that would easily break the windscreens around at that time (1970s).

Well, it came to pass that a very well-known windscreen replacement shop went to court for spending the weekend speeding up and down the highway throwing as many stones as possible to drum up business.

Back to topic.
Thanks for sharing your experiences. I guess I have been in a dream situation. I can't remember when I last had a flat tyre. It must be well over 10 years ago. Then I bought a Penguin clocked up over 10,000km since last November, and discovered this week that one of its tyres is down from 40psi to 25psi. So, reality has set in. Yet another thing to keep an eye on. Backpacks don't get flat tyres.

cheers
Mike

 

[Dean Anderson]

@mikerezny funny thing about my speculation is the way the tyre shop was open on a Sunday in a town with nothing else open, and the way the service guy threw in the excuse of National Parks not being careful when they took an old shelter to the tip, they must have dropped a few screws.....almost 20 years and I still remember the guy....or maybe I remember because he lost the hub cap off my brand new car and I had to ask him to find it?

 

[mikerezny]

@mikerezny funny thing about my speculation is the way the tyre shop was open on a Sunday in a town with nothing else open, and the way the service guy threw in the excuse of National Parks not being careful when they took an old shelter to the tip, they must have dropped a few screws.....almost 20 years and I still remember the guy....or maybe I remember because he lost the hub cap off my brand new car and I had to ask him to find it?

Yep,
I made sure this guy ever got another dollar from me. Maryborough was a small town back then, word spreads fast, so I am sure I wasn't the only one to feel that way.
Luckily, I wasn't one of the many that had their windscreen broken by him.

How's that new van going?

We have withdrawal symptoms. Couldn't go out last weekend, nor this weekend, nor next weekend.

Have a good weekend.
Mike

 

[Dean Anderson]

Having lived in the 20.64 for a few months after the 17.68? , the extra 3ft means a lot.....The bathroom is a mile better, the full two door fridge is fabulous, and having bought an annex............

Well......thanx Australia Wide Annexes......great product.......great price.....great install guy............

Our last annex was from Kakadu at the gold coast....The AWA I believe is a ,much better buy.

Can't wait till we get in the new house so we can leave it and go camping again.

Use the van as our holiday instead of our house, I mean, I dunno..........love having the consistency of a house a home...but when my family is with me in the van.....the van is my home..

 

[mikerezny]

Having lived in the 20.64 for a few months after the 17.68? , the extra 3ft means a lot.....The bathroom is a mile better, the full two door fridge is fabulous, and having bought an annex............

Well......thanx Australia Wide Annexes......great product.......great price.....great install guy............

Our last annex was from Kakadu at the gold coast....The AWA I believe is a ,much better buy.

Hi @Dean Anderson,
seems like you are much happier with it than just after handover

On the week we were expecting to take delivery of our new Penguin, after waiting for over three months after signing the contract, we got a phone call saying there was a problem and it might not rectified before the agreed handover date.

Found out ALKO had a major problem with the weld between the backing plate and the stub axle. There first ever product recall and on the week prior to our delivery. The dealer checked ours and the entire axle assembly had to be replaced. Hadn't even taken delivery and the wheels had fallen off! Not happy Jan! But Bayswater Jayco were really good, they got it replaced and we took delivery exactly as arranged.

Thankfully @Dobbie and others calmed me down during those weeks with their wise, experienced, and soothing words.

But that is all in the past. No problems with the wheels and we have clocked up over 10,000kms.
They fixed numerous warranty items at the three-month service and everything was done well.

8 months on and we absolutely love our Penguin.

cheers
Mike

 

[mikerezny]

Having lived in the 20.64 for a few months after the 17.68? , the extra 3ft means a lot.....The bathroom is a mile better, the full two door fridge is fabulous, and having bought an annex............

Well......thanx Australia Wide Annexes......great product.......great price.....great install guy............

Our last annex was from Kakadu at the gold coast....The AWA I believe is a ,much better buy.

Hi @Dean Anderson,
seems like you are much happier with it than just after handover

On the week we were expecting to take delivery, after waiting for over three months after signing the contract, we got a phone call saying there was a problem and it might not rectified before the agreed handover date.

Found out ALKO had a major problem with the weld between the backing plate and the stub axle. There first ever product recall and on the week prior to our delivery. The dealer checked ours and the entire axle assembly had to be replaced. Hadn't even taken delivery and the wheels had fallen off! Not happy Jan! But Bayswater Jayco were really good, they got it replaced and we took delivery exactly as arranged.

Thankfully @Dobbie and others who calmed me down during those weeks with their wise, experienced, and soothing words.

But that is all in the past. No problems with the wheels and we have clocked up over 10,000kms.
They fixed numerous warranty items at the three-month service and everything was done well.

8 months on and we absolutely love our Penguin.

cheers
Mike

 

[Dean Anderson]

@mikerezny yeah much happier with the van now...the initial shock and disatisfaction has minimised its-self over time. The shock of the incompetence of the salesman at Jayco Mackay has also flat-lined...............I bought a Jayco expecting dramas...but when the dramas hit you directly, they do hit you directly.

Don't get me wrong...I love my Jayco van...especially considering price and quality.

I just hate dealing with salesman that rely on sales for there living and don't know their stuff.

As a client of Jayco Australia I expect Jayco Australia's representatives to know their stuff.....

 

[Crusty181]

Aust design law say all vehicle, trailer etc tyres in Aus have to comply with a number of listed local and International standards.
Another laws say tyre info needs to make an appearance on the compliance plates, and those tyres obviously need to be up to the task.

What it seems to be in absence of any qualifying info, is that what's on the compliance plate is merely an example, and not necessarily any reference to what is actually fitted at the time. Which kind of makes sense to me. Its a starting point for those not wishing to delve deeper into the full scope of options open to them; and happy to be told, and to stick to what they're told.

What the law doesn't seem to say is that the tyres on (In our cases) the caravan have to actually be the tyres listed on the plate. So long as the tyres listed on the plate, and the tyres actually fitted fall within the scope of the standards, that's all that required to comply.

We have AFP police unable to question terrorists at the freaked airport, don't expect too much from the tyres rules.

 

[Crusty181]

My presumed causes of the above are below:

For whats its worth, under inflation causes heat build up, the lower the pressure the more heat. Prolonged over heating will then cause wall failure and/or tread separation like that. Slow leaks are the long term traveller's enemy

 

[Drover]

Well like weights there are heaps of theorys and most are BS, just like compliance plates if they can't get most of the info right on something that is a legal requirement why believe any other info that they say, I would follow the the makers fact sheet not some van builders info....The make all these laws but nobody to check them, self regulated means not regulated.

 

[Boots in Action]

Hi @Drover,
thanks for providing the very helpful spreadsheet.

I am a complete newbie in this area and it seems very important that I get the pressure correct on the tyres of our Penguin.

One tyre looked a bit down. It was 25psi, the other was 38psi, the spare was 40psi. Never touched since it came back from its 3-month service. So I wanted to pump it up and check if it has a slow leak.

So here is what I have
GT-Radial ST6000 KargoMax 185R14C
Single Axle Max Load: 900kg
Max Pressure: 65psi, 450kpa

Penguin, Tare 964kg, ATM 1264kg.
Estimated load 250kg, measured Towball weight 127kg
Estimated weight on axles: 964kg + 250kg - 127kg = 1087kg

Plugging all the above into your spreadsheet gives a recommended pressure of 39.25psi.

Have I done this correctly?

If so, here are two questions:
The compliance plate on the van states 352kpa (51psi) to 414kpa (60psi) for max loading.
I gather that I should completely ignore this and go entirely on the tyre manufacturer's specifications and estimated load.
Is that correct?

Although the tyre clearly states a maximum pressure of 65psi, it also states "never inflate beyond 40psi"
This seems to be a complete contradiction. Have you any idea how to interpret this?
<<< EDIT >>>
my bad! Ignore this question. My anti-theft chain was covering the a key part of this information.
It actually states "never inflate beyond 40psi to seat beads"
<<< EDIT >>>

Although, the post is directed to Drover, I would be very happy for anyone else to also chime in.

kindest regards
Mike

Hello @mikerezny , I too have a Penguin as you know and very similar Tare and ATM. When I picked up the van (second hand- only 18 months' old!), I found dust caps to be green coloured indicating nitrogen filled. This supposedly makes tyres last longer and reduces heat build up. Finally decided to check pressures whilst on trip to NQ because seemed to be wearing on outside edges - pressure of 29psi hot. Thought the van was a bit "mushy" so increased pressure to 45psi cold. Much better towing although a little more bouncy and wear now more even across whole tyre. I am currently running LT tyres - too dark to go and see further details. This is very complicated. I think i will stick with solar power and panel connections!!!

 

[Drover]

http://www.carbibles.com/tyre_bible.html

All things tyres and wheels, one stop information link but be prepared to spend some time.

 

[mikerezny]

Hello @mikerezny , I too have a Penguin as you know and very similar Tare and ATM. When I picked up the van (second hand- only 18 months' old!), I found dust caps to be green coloured indicating nitrogen filled. This supposedly makes tyres last longer and reduces heat build up. Finally decided to check pressures whilst on trip to NQ because seemed to be wearing on outside edges - pressure of 29psi hot. Thought the van was a bit "mushy" so increased pressure to 45psi cold. Much better towing although a little more bouncy and wear now more even across whole tyre. I am currently running LT tyres - too dark to go and see further details. This is very complicated. I think i will stick with solar power and panel connections!!!

Hi @Boots in Action,
yeah, our tyres have the green caps and are supposed to be filled with 100% Nitrogen.

Can't see much reason for sticking to Nitrogen. If I need to pump them up or replace the tyres, I am not going to go hunting all over the place trying to find Nitrogen.

So now my tyres have somewhere between 78% and 100% nitrogen and I fill them with air exactly as I do with all the car tyres I have ever had.

My tyre dealer said that the advantages are only minimal.

I am now running 40psi on the Penguin, 38psi on the front and 42psi on the rear of the Falcon. BUT, I had to pull up a bit quickly in the rain last weekend and one of my rear tyres aqua-planed before the anti-lock kicked in. I haven't had that happen before, so I may knock the rear tyres back to where I have always had them: 40psi. Also kicked the electric brake controller for the van brakes up a notch from 5.5V to 6.0V.

Found an old foot-operated tyre pump in the shed. Still works and has a pressure gauge, so it is now permanently in the boot. More kit. But since I got the slow leak and a new tyre, it prompted me to take more interest in checking tyre pressures regularly. I even checked the wheel nuts on the Penguin when we got to Vaughan Springs last weekend after travelling 150km from when I changed the tyres.

cheers
Mike

 

[Boots in Action]

http://www.carbibles.com/tyre_bible.html

All things tyres and wheels, one stop information link but be prepared to spend some time.

Thanks for the link @Drover . Time spent getting better educated is never wasted, regardless of how long it takes to go through it!!

 

[Boots in Action]

Hi @Boots in Action,
yeah, our tyres have the green caps and are supposed to be filled with 100% Nitrogen.

Can't see much reason for sticking to Nitrogen. If I need to pump them up or replace the tyres, I am not going to go hunting all over the place trying to find Nitrogen.

So now my tyres have somewhere between 78% and 100% nitrogen and I fill them with air exactly as I do with all the car tyres I have ever had.

My tyre dealer said that the advantages are only minimal.

I am now running 40psi on the Penguin, 38psi on the front and 42psi on the rear of the Falcon. BUT, I had to pull up a bit quickly in the rain last weekend and one of my rear tyres aqua-planed before the anti-lock kicked in. I haven't had that happen before, so I may knock the rear tyres back to where I have always had them: 40psi. Also kicked the electric brake controller for the van brakes up a notch from 5.5V to 6.0V.

Found an old foot-operated tyre pump in the shed. Still works and has a pressure gauge, so it is now permanently in the boot. More kit. But since I got the slow leak and a new tyre, it prompted me to take more interest in checking tyre pressures regularly. I even checked the wheel nuts on the Penguin when we got to Vaughan Springs last weekend after travelling 150km from when I changed the tyres.

cheers
Mike

Hi @mikerezny , I too have also added normal air to my nitrogen filled tyres as I have also heard that the dilution does not drastically affect what is mainly in there. When I had the tyres changed at Bob Jane's, I had the newer tyres filled with nitrogen again for very small cost.
My van brake controller is a Redarc Tow-Pro which has manual over-ride or automatic. In auto (after you set it up) the van brakes are in the same proportion to the tug's braking force, which is great for normal road/highway use. Have only needed to switch to user controlled mode one time when was going down a steep and loose incline and needed to keep the braking of van on a bit to make sure it stayed behind me. Unfortunately, every time the tug goes in for a service and they disconnect the power to do servicing, the auto Redarc function needs to be reset. And you only find out about it after you connect up the van and apply the first braking session. The van brakes come on harder than you want and that reminds you to look for the little blue light (which isn't glowing - green light in its place!) and you have to go through the reset procedure on the road. Still a very good system.
Good idea to check wheel nuts after about 100 km if wheels have been removed. I know of a vanner who changed his wheels around and although swears he had them tight, had the misfortune of having a wheel come off after travelling about 1000 km. He now checks after wheels have been removed by him or tyre fitter at about the 100 km mark.

 

[Drover]

Nitrogen is a big con, may work on race cars but total waste for general use..............we trialled it in the trucks and the general consensus was it may look good on the drawing board but not in the real world, the whole system ended up gathering dust at the workshop afterwards.

Alloy rims best to use a torque wrench on them when cold then a short bar (10") socket an hour down the road to just do a nip test, no gorilla arm job and they should be good for ages.....always check wheel nuts before leaving the workshop on car and van.

Using a Gorilla arm on wheel brace on hot rims regularly can lead to a stud parting company eventually.

 

[geedub]

Normal air is 78% nitrogen, they claim the nitrogen is more stable and doesn't leak as much as the molecules are larger. Add dry air to your tyres and if what they claim is correct the 21% O2 and the 1% argon will leak away and you will have nitrogen filled tyres .

What is true is that the nitrogen is very clean and dry but mostly it is a con to get more money out of your pocket.

 

[bigcol]

yep, I had the new fangled Nitrogen filled tyres on my Van

they leaked

let it all out, and re-fill with air from compressor

WOW has not leaked since..........