# Camper tyres pressure



## GMJ (Jun 24, 2014)

As I have mentioned before, we had a blow out on the M6 last week and yesterday now we are back home, I took the wheel in to get a new tyre fitted. As it is only 1 tyre I kept it the same as the other one - A Michelin Agilis CP tyre.

I asked the chap running the tyre depot to fill it to 55psi which is what I run all the others on (we have a 6 wheel TAG axle MH) and he said not to. We had a decent conversation and he strongly advised me to run them all at 70psi which is their maximum. He claimed it would not affect the ride plus they would wear better. They were designed to be run at such levels of pressure. he did explain the technical reasons regarding the ply etc etc but most of that passed me by :grin2:

Given that he owns the place plus has the contract to provide tyres for AAA Caravans and Motorhomes (a large dealer in Carmarthen) I guess he knows what he is on about but I'd like to hear folk's views on this.

I have decided to follow his advice and give it a go for our next trip. I should be able to compare after a decent run.

I did mention this in another thread but I thought I'd start a new thread and would be interested in other MH owners views on this. 

ta


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## JanHank (Mar 29, 2015)

I have been told the same thing Graham, the men in my village who have driven delivery vans say I should use the pressure given on the tyres and each time I ask for lower pressure from my man I discover it’s still The same pressure given on the tyres. I gave up.


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## GMJ (Jun 24, 2014)

How do you find the ride Jan?


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## JanHank (Mar 29, 2015)

The same as it’s always been Graham as I have never had anything to compare. Motorways and good roads smooth, bumpy and repaired roads —— bumpy 😉


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## EJB (Aug 25, 2007)

Just a very few years ago it was accepted by the various transport bodies *for all white vans* that the dictate for tyre pressures should be 70 or 80 PSI.
Myself and many others have emails and verbal advice from various tyre manufacturers (In my case Michelin and Continental) where 45 to 65 PSI is perfectly acceptable in my particular case!
There are of course a couple of tyre sites that offer the weight/pressure calculations for various tyres!
The decision is yours!!!:wink2:


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## Pudsey_Bear (Sep 25, 2008)

I'm not certain but on our tyres, the pressure indicated is a MAX not running pressure.


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## GMJ (Jun 24, 2014)

My inclination is that it is too high but given the advice I'll try it out. I have only run at 55psi-ish so have little to compare it to really.

I'll take a tyre pressure gauge with me (thanks Ray







) and can always adjust for the return trip.


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## GMJ (Jun 24, 2014)

Right, I went out to check my tyre pressures armed with my new gauge and also my Ring RAC900 ready to inflate. 

Upon checking my pressures they were at 70 Psi all around already! I was not expecting that I can tell you and I feel a bit of a duppa now having suggested to the tyre bloke that I have them at 55!!!

Still as we are happy with the ride and the wear looks even, no worries!

...bit gutted I couldn't use my inflator though!


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## Pudsey_Bear (Sep 25, 2008)

I have a knife you can borrow G.


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## GMJ (Jun 24, 2014)

Actually there is a right twunt of a bloke who lives in the village who is also a MH'er unfortunately so it is tempting...

Myself and Mrs GMJ went for a walk after lunch today and when we heard a vehicle behind us we stopped walking to let it through as there was a car parked and it would have been a little tight. The twunt barrelled through in his MH without even a wave of acknowledgement. As his window was open i shouted "Don't mention it"! Next he stopped and rammed it into reverse to where we were and belligerently asked if I had made a comment. I suggested that it would have been nice to perhaps wave as thanks for letting him through, to which he drove off!! I followed up with "Have a nice day" as I couldn't help myself


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## Pudsey_Bear (Sep 25, 2008)

I might have done the same G


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## Pudsey_Bear (Sep 25, 2008)

But I might have run you over too😛😛😛


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## dghr272 (Jun 14, 2012)

*Michelin CP stamped max pressure change*

Interesting post from FB.

Terry


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## Glandwr (Jun 12, 2006)

GMJ said:


> Actually there is a right twunt of a bloke who lives in the village who is also a MH'er unfortunately so it is tempting...
> 
> Myself and Mrs GMJ went for a walk after lunch today and when we heard a vehicle behind us we stopped walking to let it through as there was a car parked and it would have been a little tight. The twunt barrelled through in his MH without even a wave of acknowledgement. As his window was open i shouted "Don't mention it"! Next he stopped and rammed it into reverse to where we were and belligerently asked if I had made a comment. I suggested that it would have been nice to perhaps wave as thanks for letting him through, to which he drove off!! I followed up with "Have a nice day" as I couldn't help myself


Control youself G :laugh::laugh::laugh: as to tyres, to run at a pressure purely to prolong the life of tyres makes no sense for me on a MH. I have never changed my tyres because they have been bald. I've changed them because of age though.


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## KeithChesterfield (Mar 12, 2010)

When we first had a Motorhome about a decade ago I topped the pressures up to 80psi as stated on the door frame.
It was like riding on a 'corrugated' surface and it needed extra adhesive for the dentures and barnet to keep them secure.
After seeing the Continental and Tyre Safe recommendations and pressure charts I had the axles weighed, took the Tyre charts seriously and reduced the pressures accordingly.
The 'ride' was considerable less bumpy, smoother, more comfortable and no noticeable difference in handling.
With the tyres I have fitted on my currrent Motorhome - Continental (225/70 R 15C 112/110) - on my Pilote on a Ducato base and with front axle 1560kg and rear axle 1940kg, confirmed fully laden by a weighbridge, the recommended pressures are 47psi front and 61psi rear.

Regarding the Tyre Depot blokes advice – I would imagine many of his clients are White Van Man drivers or even heavier vehicles who do a considerable yearly mileage at fast speed and they aren't bothered about a few more rattles and wear to the vehicle as long as the tyres don't wear too quickly.

As said earlier most Motorhomers don't change tyres because of wear but usually because they have exceeded the age at which tyres should be replaced – often between 5 and 7 years.

We rarely do many miles in one go, except for the sprint to Eurotunnel, driving as comfortably as possible, and I wouldn't imagine many of you drive 'ell for leather very often, so I prefer the 'softer' ride of the Motorhome compared to the higher inflation and harsher ride.

Everyone to their own …..

:nerd:


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## Pudsey_Bear (Sep 25, 2008)

What about possible insurance complications should an incident become related to low tyre pressure?


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## erneboy (Feb 8, 2007)

If the pressure has been recommended by the tyre manufacturer the insurers will be happy with that.


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## Cherekee (May 1, 2005)

I have been running mine at 51 (47psi + 10% as advised by Continental Tech) Front & 55 psi Rear for the last 13 years. Not been a problem for me summer or winter with my Continental 4 Season tyres. Try getting out of a snow pack with 80 psi in and you will be able to sell tickets. I will not even mention the aquaplaning performance reduction at 80 PSI either.

Alan


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## dghr272 (Jun 14, 2012)

dghr272 said:


> Interesting post from FB.
> 
> Terry


Update

The Michelin response to the FB member.

Terry


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## Pudsey_Bear (Sep 25, 2008)

Hmm, I have Agilis tyres, not even considering 80 PSI


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## Penquin (Oct 15, 2007)

Hhhmmm, it does say the 80 can be adjusted down to 65 for "*comfort and optimal performance"*

Surely "optimal" means "the best"

*Oxford Languages Dictionary;*

_optimal_ adverb - the best, most favourable, most desirable or satisfactory

Why would you risk using something that you have been told and KNOW is NOT the best ?


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## 242633 (Oct 21, 2021)

Penquin said:


> Hhhmmm, it does say the 80 can be adjusted down to 65 for "*comfort and optimal performance"*
> 
> Surely "optimal" means "the best"
> 
> ...


Here goes my infamous 'Open mouth only to change feet manouevre' :smile2:. Whilst the Oxford Dictionary may give an accurate definition of 'Optimal', the author of the reply from Michelin Technical Support may not have consulted the Dictionary ... My interpretation of the reply, based on my, ahem, extensive motorhoming experience of 7 months tomorrow, is that he really meant 'best balance' or 'trade off' between load capacity and dental filling protection.

But I could be wrong; I have a long history of so being, in fact, if I entered 'Mastermind', 'Being Wrong' would be my Specialist Subject ...

Steve


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## Penquin (Oct 15, 2007)

I like that answer a great deal Marchie and can identify with your position frequently, although I was obviously wrong in that I had never thought of entering ‘Mastermind’ with the specialist subject of “Being wrong”.

I was obviously wrong about that so would be ideally suited if that was possible…

However, since the letter comes from the “Technical Support” Department, I would suspect that every single word is carefully scrutinised before it is posted due to that nasty phrase “legal liability” and lawyers dissecting every single letter and any possible alternative interpretations in the event of something unpleasant happening like an rtc. You know how insurance companies like to find “wriggle room” before settling or rejecting a claim.

But, I am probably wrong yet again….. (Beat you as I used the word 5 times c/w two for you - or am i wrong about that too ?). 😱. 🤐. 🤣


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## 242633 (Oct 21, 2021)

Penquin said:


> I like that answer a great deal Marchie and can identify with your position frequently, although I was obviously wrong in that I had never thought of entering 'Mastermind' with the specialist subject of "Being wrong".
> 
> I was obviously wrong about that so would be ideally suited if that was possible…
> 
> ...


I couldn't possibly comment, Penquin, because I would undoubtedly be wrong; the only issue to debate would be the margin of error ... But, the positive in all of this is that I am a reliable benchmark for other Members to measure their positive scores against. Unless I happen to be right, and that's where the complications arise, because I can develop delusions of adequacy. A moment to savour ... :smile2:

Steve


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## dghr272 (Jun 14, 2012)

marchie said:


> Penquin said:
> 
> 
> > I like that answer a great deal Marchie and can identify with your position frequently, although I was obviously wrong in that I had never thought of entering 'Mastermind' with the specialist subject of "Being wrong".
> ...


Ah yes, "delusions of adequacy" a very prevalent ailment and a much misunderstood condition not understood by non sufferers.

Terry


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## Pudsey_Bear (Sep 25, 2008)

I know at least one northern IT bloke who suffers from it, or should I say he makes others suffer from it.


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## 242633 (Oct 21, 2021)

On a more serious note, if Elaine and I are to get some Spanish Winter Sun over the next couple of months, we'll need to think about Winter Tyres for Brunhilde. The Van [registered 1/6/16] has the original tyres [Week 44 2015] and, having only 11479 miles on the clock, plenty of tread left, and no signs of tyre wall splits or cracks. The tyres are Michelin Agilis CP 225/75R16 CP with a 116 Q Speed Rating, and a 'M&S' ['not just any tyres ...'] designation, which I think meet the new French Winter Tyres Regs for High Altitudes

We will probably cut across from Bordeaux to Toulouse and cross to Spain via Perpignan, rather than travel via Irun in late November and plan returning in early February by the same route

Do I need to get designated Winter Tyres? Continentals work out at about £187 each locally, and there is an Avon owned Brand, Cooper, at about £150 fitted at the same local Tyre Fitters. I don't want to have tyres fitted unnecessarily, but I also do not want to take a stupid risk and put our personal safety and a quite expensive Motorhome at risk for the sake of less than 1.5% of Brunhilde's value, even if I go mad and buy the Continentals!

Thanks in advance for your advice

Steve


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## Pudsey_Bear (Sep 25, 2008)

I normally buy van tyres, designed to do the same job but no silly moho price hikes


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## Buzzabout (Nov 3, 2020)

*Tyre Pressures*



Pudsey_Bear said:


> I'm not certain but on our tyres, the pressure indicated is a MAX not running pressure.


You are correct Pudsey, the pressure shown is for approval tests at the maximum load that the tyre is permitted to carry.

I run the tyres on my Auto Trail Scout at 280kPa front and 450kPa rear (40psi and 65psi in old money). Those pressures are adequate for the *weighed* axle loads. The inflation pressure shown on the door pillar is 550kPa front and rear (80psi). Boneshaking, designed to make your teeth rattle and unnecessary if you have the front and rear axle weights, but be careful, don't weigh the vehicle today with no payload and set the pressures for those loads. You must weigh the vehicle with its normal maximum payload on board.

Excessive front pressures can lead to dynamic instability, not good.

Using excessive pressures will affect your tyre life, that is to say reduce it.


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## raynipper (Aug 4, 2008)

Not disputing anything you say Buzz but who on earth dreamt up 'kps' measurements. Don't we have enough to try and get out heads round?

Ray.


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## Pudsey_Bear (Sep 25, 2008)

Does it mean kg pet atmosphere or something.


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## raynipper (Aug 4, 2008)

It's this Kev. https://www.thoughtco.com/definition-of-kilopascal-604551

But do we actually need to change from what is well known both sides of the channel?

Ray.


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## Pudsey_Bear (Sep 25, 2008)

I got lost when we had bar to contend with, to my mind the smaller the unit of measure you use the more accurate you will be So psi wins.


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## raynipper (Aug 4, 2008)

We have had to adopt and get used to all sorts of new and old quantities. Imperial & Metric in material and foodstuffs. But we do adapt but sometimes it's a juggle.

Ray.


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## Penquin (Oct 15, 2007)

Blood glucose is measured using two different units in the U.K. and very many other places….

mg/dl or mmol/l

Please don’t ask me to explain, that’s above my pay grade….. but one is 18x higher than the other…. (eg 10mmol/l = 180mg/dl) Quite a considerable difference……

A few years ago blood glucose meters in the U.K. used to be switchable between the two systems…..

Recipe for disaster as one elderly person suddenly found a blood glucose reading of 90……

Panic, panic ‘cos most of his readings were around 5.

So, thinking things were desperately wrong he gave himself boost after boost of rapid acting insulin and was found collapsed. Fortunately the hospital was able to treat with a glucose drip (probably more of a glucose flood than drip) and we’re able to work out how the confusion had happened. His case was far from unique.

No such switching is not permitted ANYWHERE, but it does show how the units involved MUST be understood before use.

So beware of kPa, b, and psi - don’t mix em up…. Tyres will go bang if inflated to 65 b and as for kPa, don’t even think about it as the rest of the MH could end up on the moon.


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## dghr272 (Jun 14, 2012)

Having worked 8 years in Michelin actually putting all the bits of rubber, steel and fabrics together that make up a tyre and understanding the process Michelin put into tyre development, I'd ignore their advice at your own peril.

For those of us that put all the elements together, they employed 5 times as many in QC proving they met their high standards of uniformity criteria or otherwise run a gully knife through the sidewalls of the worst of the cured tyres making them only useful as dock boat fenders. The only element that could be reused before a tyre was cured was the steel 'tringle' bead band that provided the support for the wheel rim seating.






Terry


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## GMJ (Jun 24, 2014)

I run ours at 70psi all around and am happy with the ride and the wear patterns. We normally are running with a fairly full load as well...anything up to the full 5t.


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