Michelin Tyre Pressures
I know there has been few threads on this but below is an email from Michelin regarding the Agilis camping tyres I got from another site. It was the same advice given to me via a chat.
Thank you for contacting MICHELIN Customer Service,
Regarding your query, we only have the pressure recommendation for our MICHELIN Agilis Camping.
The pressure recommendation for the rear (single) axle of a motor-home running on the MICHELIN Agilis Camping is 80 PSI. This is due to the construction of the tyre with 2 casing plies enabling the use of higher pressures.
It’s construction and the use of higher pressures is designed to cope with continual heavy loads sometimes found on motor-homes and can help with wear pattern issues, if lower pressures are used particularly on the rear axle.
The front tyres however can be adjusted down to a pressure of 65 PSI for a more comfortable ride and optimum performance.
Here are some safety points to be taken into account when it comes to tyre
pressures:
1. Always check the pressures when the vehicle tyres are cold. We consider
the tyres being cold if they haven’t been used for at least 2 hours of it
they have rolled less than 4 km at low speed. If the tyres are not under
this conditions they are considered to be hot.
2. When the tyres are hot you should always add 4,4 PSI to the recommended
pressure.
3. Please remember - Never deflate a hot tyre!
I hope this information was helpful and please do not hesitate to contact
us again if you have any further questions or concerns. We are happy to help.
Kind regards,Dora
MICHELIN Customer Care
Passenger Car & Light Truck Tyres
Comments
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I think Michelin have been saying this for some time. Both motorhomes I have owned required 80 psi in the rears but where they seem to move away from the Michelin recommendations is the original motorhome had 55 psi at the front and the new one needs 50 psi. An added complication is that all new motorhomes are now fitted with a factory fit tyre pressure monitoring system so it's not so easy to move away from the recommended pressures as it usually requires dealer intervention.
David
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If I understand that aright, that's a bit worrying as it appears to be a stock answer. I gave details of my van's weights (Laika Ecovip 600 downplated to 3500kg) to see if the manual's recommendations were changed because of downplating. Seemingly they no longer offer recommendations based on the actual weight of an individual van.
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You can use the TyreSafe Motorhome Tyre Inflation Pressure Advice - https://www.tyresafe.org/check-your-pressures/motorhomes/ - to find what pressures they advise for your vehicles tyres..
I'm never sure why Motorhomes are run at the tyres maximum, usually 80psi, which gives a harsh ride and on many roads could dislodge your false teeth and certainly rattles the chassis with the hard tyres and no 'give'.
You need to know the front and rear axle weights (around £5 to use a local weighbridge) and the size and type of tyres you have before adjusting your tyre pressures.
Any guesswork will mean your tyres probably won't last as long and may wear unevenly.
With the tyres I have fitted - 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.
Michelin have always recommended the maximum pressure in their tyres, and many of you will continue to take their advice, but those who have actually weighed their vehicles and reduced pressures will know what a big difference to ride and comfort is achieved.
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Hi everyone. Old thread I know but just tackling this dilemma with our new Malibu Van. The Malibu instruction manual provides the attached seemingly helpful table. Our tyres are the 225/75 R16 CP 116Q and the recommended pressures fully laden would be 3-3.5 bar (44-51psi) .... way lower than the Michellin guide for the rear which is recommending a silly high pressure for the rear. Tyresafe does as well. Is there something about the dynamics of a rear wheel in motion, sideways forces or the characteristics of these specialist 'camping' tyres etc. Ours is a PVC rather than coachbuilt. Does that make a difference? Call be confused. High pressures leads to a dreadful ride.
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We also have a Carthago and the same tyres. I have found that the best way of establishing the right pressures is to put the van into fighting trim and get it weighed. You need to have 90% or above fuel, all the passengers you would normally carry, yourself, and the water tank filled to the maximum level you would normally travel with. We travel with full water (170 Ltrs). Make sure you have all the clothing and equipment on board that you would normally carry. At your local weighbridge get two or three checks, the full weight, and front and rear axle, or just two and do a calculation. Phone or email Michelin product support with the info and ask for recommended tyre pressures. They are very helpful.
Alternatively, also in full fighting trim, use the relatively low pressures you have quoted and drive for about 20 miles, park and place your hand against each tyre. At ambient OAT they should be just comfortably warm, not cold and definitely not hot. Heat is the biggest killer of tyres. If hot add about 10 psi and repeat the test in about 10 miles. Others may disagree but this is a well proven means of ensuring you are not running the tyres too soft.
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Try the Tyresafe website. I ahve printed off one of there documents and keep it in my caravan:- https://www.tyresafe.org/motorhome-tyre-pressure/
Colin
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Did you have to recalibrate the tyre pressure warnings and, if so, how? I've been running mine at the pressures on the sticker on the gas locker door, 5 front and 5.5 rear. My axle loads are similar to yours in battle trim. Some of the minor roads are a bit uncomfortable!
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This " pigheaded Dutch selfdeclared tyrepressure-specialist " came to this topic, and the list given is strangely composed, cant figure out what they done the 225/75R16 Michelin CP only gives 116 loadindex is 1250kg maxload a tire, but 2550kg axleweight given at 5,25 bar is 50 kg more then 2x 1250kg.
But I made my own calculator, so only use these lists to determine the maxload and reference-pressure ( pressure behind AT, but Continental gives often also max inflation pressure on sidewall, is also cold pressure)
Then I add first 10% to the determined axleload( spreadsheet does that , so dont do it double), and then calc it with safer formula then the original of ETRTO.
Then outcome will be higher then those read from the lists.
Will try to give link to motothome-map on my public map on onedrive that belongs to my hotmail.com adres with username jadatis( combine yourselfes if you want to mail me, spamm robots cant this way)
Did not work on my mobile, so mail me , or give data here.
To be continued later.
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Motorhome-tyrepressurecalculator-map
Download the spreadsheet and open it in Exell or open offic3 Calc.
But also possible to use it directly in browser, but then next will see your data.
I dont see the extra vallue of CP over C or LT,to my opinion a marketing trick.
And because of the strange things in motorhome makerlist, I also would trust the tyremakers list better.
You can also navigate my complete public map , fi to pressure/loadcapacity lists I made with extra safe formula. But then you have to add first yourselfes the 10% reserve.
Loadcapacity is given for 160kmph/99mph., and max speed used with motorhomes is 130kmph/81mph, so this gives some extra reserve before tyres overheat.
I determined that if weight on tire is lower then 85% of loadcapacity belonging to the pressure for 160kmph/99mph, that then comfort and gripp is still acceptable.
Using 10% reserve makes average on the axle 91% , so if unequal loaddivision makes one side 85% and other side 97%, still acceptable comfort and gripp, and no overheating at 99mph.
Overheating must happen zero times i tyres live.
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Thanks for that but what have you done about the tyre pressure sensors?
Motorhome Fun had a fair number of post saying the Michelin Camper tyres don't provide much grip apart from the pressure issues. I've not found performance issue apart from the hardness of the ride. One wonders if reducing the pressures would adversely affect lateral stability. I'll be looking at new tyres in the next 18 months anyway so will have to decide whether to do like for like or switch to something else.
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Yet another tread resurrected from the tomb
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Only because someone has liked a post in this discussion. Clearly some members do trawl back through the various posts and hopefully find some of them useful and as a result like them? Threads don't usually magically reappear without an action. People are free to check latest activity to see what has happened.
David
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Tyre pressures are not only determined by axle load. Vehicle handling also plays a part. Raising the rear tyre pressures, or lowering those at the front, will correct oversteer and the opposite will correct understeer. In addition, some manufacturers recommend increasing tyre pressures simply to reduce fuel consumption.
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