# interesting tyre pressure recommendation



## Sprinta

I took the MH into a weighbridge recently and then emailed Michelin for pressures on my Michelin Agilis Camping tyres for my Riviera 171 and got the following...........

front axle @ 1560kg is to be 51 psi

rear axle @ 1860kg is to be 80 psi

all 4 were set at 70 psi when I had new tyres fitted last year.


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## mikebeaches

I believe Michelin always recommend 80 psi these days for rear axle, regardless of weight.

Thankfully, I've got Continental tyres on current MH, and the company supply more sensible rear axle pressures; ones that are properly correlated to the loading in my opinion.


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## drcotts

Hi
f you have a fiat or peugeot the tyre pressures should be on a label inside the door jamb. 

These are the recommended pressures for your tyres. 

You will get lots of conflicing and differing advice depending on who you ask but the ones written there are the official ones and the ones you will be challenged on should the need arise.
Lots of people dont realise it there..

Hope this helps

Phill


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## Techno100

I don't agree Phil. That label is fitted before conversion and applies to vans I believe. My label says 79psi all round
After a whole year of experimentation I now drive with 55 front 75 rear. The gap has grown over a long period as I've put more gear on affecting the rear weight. If anything the front will be reduced some more yet.


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## motormouth

Oh dear Phil. I fear you have opened another can of worms on this subject which shouldn't have been opened.
If I went by the pressures given on the door plate, I would be driving a steam roller, 80psi front and rear. On advice from Continental after giving them my actual axle weights, I run with 48 front and 60 rear.
I am tempted to remove this confusing plate or at least try to overwrite it with the above pressures.


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## Vennwood

I partly agree with Techno100 - the labels are put there before the conversion and don't apply to the converted MH 
I don't think that experimenting is the best way to determine pressures though. What about the law/insurance on that in the event of an accident? 

I don't agree with mikebeaches either as Michelin will give you pressures specific to weight, size, type etc..

To support this I look at my own situation.
Label under bonnet on our Iveco (and Iveco manual) give loaded pressures as 55/55psi 

In the N+B handbook pressures are given as 65psi front, 70psi rear.

When I went to weighbridge and then passed details to Michelin they came back with 70psi front and 75psi rear.

All very confusing

I decided to go with Michelin as they made the tyres and therefore should be in a better position to know what's best for the tyres they designed and manufactured.

Ironically the N+B front pressure of 65psi does give the best ride :?


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## rickwiggans

As have many people on here, I have contacted my tyre manufacturer for a recommendation - and I carry the print out of their reply with me in the van


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## loughrigg

drcotts said:


> Hi
> f you have a fiat or peugeot the tyre pressures should be on a label inside the door jamb.
> 
> These are the recommended pressures for your tyres.
> 
> You will get lots of conflicing and differing advice depending on who you ask but the ones written there are the official ones and the ones you will be challenged on should the need arise.
> Lots of people dont realise it there..
> 
> Hope this helps
> 
> Phill


Sorry, Phil but I disagree - and so does the Peugeot commercial vehicle main agent that I consulted about my tyre pressures. I posted this extract on a thread yesterday, so apologies to anyone who has already read it.

"A Peugeot commercial vehicle main agent has stated that the records of the vehicle show that the base was supplied as a "bare chassis for conversion". Accordingly, the advice from Peugeot is

"the tyre pressures specified in the handbook supplied with the vehicle or appearing on the door pillar should not be used as definitive statements of required tyre pressures as they relate to the vehicle only at the point of construction".

Peugeot's position is that as they have no knowledge of the manner or type of conversion, they cannot and will not recommend an appropriate tyre pressure for the vehicle. This is based upon the possibility of changes being made to the gearbox and/or suspension post-production (by the converter) that are unknown to Peugeot and which could change recommendations relating to the vehicle in standard (production) configuration.

When asked if they could confirm the size of tyre that should be fitted to the vehicle the answer was similar - without knowing full details of the conversion and any associated gearbox/suspension modifications, they could only confirm the standard tyres at production which might or might not be appropriate tyres post conversion.

Ultimately, Peugeot's advice was to refer to the vehicle converter who would be able to advise details of any post-production modifications and recommend the correct tyre pressures for the tyres they (the converter) deemed appropriate at the time of conversion."

Mike


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## andrewball1000

This thread may be relevant http://www.motorhomefacts.com/ftopict-101081-.html


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## EJB

My experience:-

New Agilis campers fitted 18 months ago.
Max axle weights...Front 1650....Rear 1750.

Actual weighbridge weight...fully loaded...Front 1280....Rear 1760.

Michelin recommended pressures based on the actual weight...Front 50PSI...Rear 55PSI.

Front axle pressure allows for weight transfer when braking.

10,000 miles later and they have even wear and tyres only warm during a run.

HTH


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## DTPCHEMICALS

Sorry Phil,
My door jamb sticker states 90psi.

Hankooks Max is 65psi.

I have e fronts at 63 and rear at 65.
Comfortable and quiete ride.
Different manufacturers will give different settings to comply with there own tyres.

Dave p


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## Hymervanman

I also drive a Mercedes Vario 7.5 tonne panel van which has an unladen weight of 3.95tonnes
The handbook clearly states different tyre pressures for different axle weights and different tyre sizes 
Moral of story would seem to be that tyre pressure is specific to the tyre size and axle weight and to therefore check with your tyre supplier after weighing the vehicle


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## icer

Hi

I contacted Michelin by e-mail, with the following information in march 2009.

Actual loads
Front 1700kg Rear 2300kg on 215/75 R16 C XC Camping Tyres

Gist of response, as they say that info should not be disclosed or copied, is,

Due to surveys many motor homes have been found to be overloaded especially rear axle.

Manufacturers therefore build in a safety factor by fitting strong tyres, inflated to high pressures. In order to reove the potential for consequences of overloading&/or under-inflating the tyres.

Drawback is the possibility of an extreemly hard ride, but that tyres will cope nicely.

It was also mentioned that the figures take into account the transfer of pressure in breaking.

In my case pressures given were, Front 65psi Rear 80psi

When I spoke to them on the phone,the guy said that the xc was very much over engineered.


Ian

Ian


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## cronkle

This link may be of interest:

http://www.conti-online.com/generat..._info/download/technical_data_book_pdf_en.pdf

It's fairly comprehensive.


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## Pudsey_Bear

Should one have a tyre related collision, which tyre pressures should we be sticking to, my guess would be to stick with the tyre manufacturers figures, but some campers might have 5 different makes of tyre on them, (we're not all money bags) with 5 different pressure reccomendations, which could cause all sorts of problems.


So what would be a the legal answer, and would the insurers use it to wriggle out of their payout :?: :?:


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## drcotts

Well i did say you would get conflicting advide didnt i?

If you had an major accident and the police checked your vehicle and found that your tyres were say 55psi how would you convince them, or a court that you had this info from a dealer, tyre specialst or whoever. If questioned and asked they would probally say err umm "i never said" that so you would have to get it in writing.

if you did get something written down then great - but whos right?

I say this not to disagree with what others have said but to show that theres so much conflicting info about no one knows what it should be and theres no way of getting a once and for all answer.

All i know is that if a copper asked me i would say "look here mate at this big daft label" this is what the manufacturer says..what else did you expect me to do?

But i take on board all then points raised and your probally right


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## mikebeaches

Vennwood said:


> ...I don't agree with mikebeaches either as Michelin will give you pressures specific to weight, size, type etc..
> 
> To support this I look at my own situation.
> Label under bonnet on our Iveco (and Iveco manual) give loaded pressures as 55/55psi
> 
> In the N+B handbook pressures are given as 65psi front, 70psi rear.
> 
> When I went to weighbridge and then passed details to Michelin they came back with 70psi front and 75psi rear.
> 
> All very confusing
> 
> I decided to go with Michelin as they made the tyres and therefore should be in a better position to know what's best for the tyres they designed and manufactured.
> 
> Ironically the N+B front pressure of 65psi does give the best ride :?


I may be wrong and I don't know how long ago it is since you contacted Michelin, but I believe they have had a fairly recent change of policy (last 12-18 months). Icer (Ian) made a similar point in an earlier post above.

Last April '10, I sent the inquiry below to the company for my previous MH + their reply.
---------------------------------------------------
Motorhome Tyre Pressure Inquiry

Please could you advise the MINIMUM safe tyre pressures for my Michelin X XC Camping tyres - size: 215/70R 15C (109/107)

I have a Rapido 709 F [Fiat Ducato cab - front wheel drive].

Last week I had the fully laden vehicle (including passengers, water and fuel) checked at the local council weighbridge.

Total weight - 3,080 kg 
Front axle - 1,560 kg 
Rear axle - 1,520 kg

Thank you

----------------------------------------------------

Dear Sir,

Thank you for your recent e-mail.

Based on the tyre size and weights provided we would suggest pressures of: 52psi (3.6bar) for the front axle tyres.

We do not recommend altering the rear axle pressures from the maximum for the tyre which is 80psi (5.5bar)

Yours sincerely

The Michelin Man


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## mikebeaches

Our current MH is fitted with Continental tyres, and I was surprised how low the recommended pressures were.

During the winter we stripped the van of most of our belongings and used it primarily as a day vehicle. However with the reduced tyre pressures advised by Continental the quality of the ride was totally transformed for the better.

Detailed inquiry made and response below:

----------------------------------------------------------

Tyre Pressure Inquiry - 01/11/10

I have a 2-berth Chausson Flash S2 Fiat- based motorhome, which has front wheel drive.

The vehicle is fitted with Continental VancoCamper tyres: 215/70 R15CP 109R.

I have just had the axle weights checked at our local weighbridge with fuel and water etc. The weights below include the driver and passenger on board

Front axle: 1,515 kg

Rear axle: 1,425 kg

(There is only a single axle at the rear)

Please could you advise the correct tyre pressures for these loads.

--------------------------------------------------------

Thank you for your recent query.

It is unusual to find the rear axle lighter than the front. Nevertheless, here are the pressures required based on the information you have provided us.

Front: 3.25 bar - 47psi
Rear: 3bar - 44psi

Regards

Product Support Engineer
Continental Tyres


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## Pudsey_Bear

What a mine field this is, there must be a definitive point somewhere, as a deflated tyre can and would create an incident.


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## Sprinta

Kev_n_Liz said:


> What a mine field this is, there must be a definitive point somewhere, as a deflated tyre can and would create an incident.


yes indeed, a friend of mine have a front tyre go pop on his motorbike last week at a meeting I was at and caused him to crash.....

he was doing around 200 mph at the time 

I'd just packed up as I had a "6th sense" feeling that I should stop


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## loughrigg

Kev_n_Liz said:


> What a mine field this is, there must be a definitive point somewhere, as a deflated tyre can and would create an incident.


It would be a lot easier if there was a definitive point of reference - but I don't think anyone has found one yet. :? :?

Having read as much as I feel able to stomach on the subject, I have concluded that the best course is to follow the opinion/guidance of the tyre manufacturer (if they will give any). The comment I managed to extract from Vredestein was fairly vague, but enough to support the opinion I had already formed - fit tyres of the correct load/speed index and take note of the recommended tyre pressure at maximum load as stamped on the tyre carcase. If running at or close to full load use that pressure. If running significantly lighter, adjust the pressure proportionately. If pressure is not adjusted relative to load, then the risk of uneven wear and reduced tyre performance is introduced.

Mike


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