What Tyre Pressures, Please?

HKF

HKF

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Benimar Europe 740
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Since August 2021
Hi everyone

Here are the tyres and info I have on my MH. Can someone tell me what pressures they should be at, please? Our MH is rated at 3,500kg.

FRONT - Michelin Agilis Camping 215 / 70 R15 CP M+S 109Q at 80psi
REAR - Continental Van Contact Camper 215 / 70 R15 CP M+S Maximum inflation pressure single / dual 79psi 109R 475 KPA

Thank you so much :)
 
My Bridgestone Duravis [same size] are at 53psi all round as recommended by Bridgestone's technical department for an actual weight of 3460kg.

79/80psi seems very high and must give a hard ride.
 
Langtoftlad said:
My Bridgestone Duravis [same size] are at 53psi all round as recommended by Bridgestone's technical department for an actual weight of 3460kg.

79/80psi seems very high and must give a hard ride.
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The psi I gave is just part of the information on the tyres themselves. The printed information that came with the MH says 75psi but we've had all the tyres changed since we bought it. On the door, it says 72.3psi front and 79.5psi rear. We currently have them at 75psi all round. I'm not sure if it's a hard ride or not, as this is our first ever MH, so I don't know what they 'can' or 'should' feel like. My husband wants to keep them at 75psi all round but I want to check we're doing the right thing :)
 
Your tyre pressures should be based on axle load, then contact the manufacturer stating the axle load. We used to run with the tyre pressures similar to you. I contacted Continental with the axle loadings (both axles are Continental) and was stunned to find out we were substantially over pressure. They provided a chart for the exact tyre and loading range. The difference was amazing, for our loadings we now run 51psi on both axles as we are evenly loaded. Make a trip to the weighbridge with the vehicle loaded as if you were going away, then you can make enquiries via their support depts. HTH
 
Vaman said:
Your tyre pressures should be based on axle load, then contact the manufacturer stating the axle load. We used to run with the tyre pressures similar to you. I contacted Continental with the axle loadings (both axles are Continental) and was stunned to find out we were substantially over pressure. They provided a chart for the exact tyre and loading range. The difference was amazing, for our loadings we now run 51psi on both axles as we are evenly loaded. Make a trip to the weighbridge with the vehicle loaded as if you were going away, then you can make enquiries via their support depts. HTH
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Same here. Went from the (I assume Ducato) pressures listed on the door frame to 58psi at the front and 65psi at the back. This was based on our maximum axle weights and the Continental chart. The difference in the ride was substantial.

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The Continental handbook will tell you the required pressures for your axle weights... but as they are "camper" tyres, it'll probably say they ought to be kept pretty high.

My Continental VanContact 4Seasons are advised to be a squishy 50psi... but they aren't Camper tyres.
 
Thank you so much for the answers above.

I guess I need to load the MH, as though we're going away, then get the axle weights, then ring Michelin and Continental.

However, just for now and going on;
  • the maximum axle weights
  • the below results from the TyreSafe calculator
  • the maximum pressure stated on the tyre walls (79 and 80psi)
we're going to go for 60psi on the front and 70psi on the rear.

Does that sound like the right thing to do, please?



1724856839932.png
 
HKF said:
Thank you so much for the answers above.

I guess I need to load the MH, as though we're going away, then get the axle weights, then ring Michelin and Continental.

However, just for now and going on;
  • the maximum axle weights
  • the below results from the TyreSafe calculator
  • the maximum pressure stated on the tyre walls (79 and 80psi)
we're going to go for 60psi on the front and 70psi on the rear.

Does that sound like the right thing to do, please?



View attachment 940957
Click to expand...
Good idea, and don't forget to include the passenger(s) when weighing.
 
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image_part_7801425563422248.png


info I got regarding a 4.5 t vehicle with CP tyres. (I actually run loaded 77psi rear, 65 psi front and smooth enough - don't feel the need for semi air.)

Thank you for contacting Michelin customer service.

Tyre pressure for the Michelin CrossClimate Camping tyre, for motor-homes and camping vans that are fitted with metallic valves with a single axle on the back and no twin wheels.
Front: Follow the car manufacturers tyre pressure recommendation
Rear: 5.5 bars / 80 PSI
Tips on tyre pressure:
- 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.
- When the tyres are hot we should always add 0.3 bars to the manufacturer recommended pressure.
- Remember; Never deflate a hot tyre !!!
Please note, for any other tyre pressure recommendation please contact the car manufacturer or your dealer.
CP tyres, have been developed for camping vehicles such as mobile homes and they have a reinforced sub structure.
CP tyres therefore have a high load bearing capacity and therefore endure a considerably higher air pressure and at the same time a greater protection from mechanical damage.
considerably higher air pressure and at the same time a greater protection from mechanical damage.
This reinforcement is done over several layers. This reinforcement protects the tyres during a long stationary period.
According to the ETRTO (2019), CP tyres are the only tyres that are allowed to have a pressure of 5,5 Bar.
It's highly recommended to use metal valves with this pressure.
MAX pressure marking that may be on all 4 Wheels tyres: These pressures are a requirement of the Canadian and United States market. They are not used in Europe.
These are the pressures used to perform the DOT tests for this tyre for Canada and the United States


Please find more information on the following link: https://www.michelin.co.uk/auto/advice/van/motorhome-tyres



For additional information please contact us by email: contact@tc.michelin.eu, on our website http://www.michelin.co.uk/ by filling in our contact form [Broken Link Removed] by phone, Mon-Fri 09:00-18:00, 08000 318 802

Michelin is happy to accompany you on every journey and would like to thank you for your confidence.



Click here to take our survey: https://michelin.cibernos.com/plan3.3/deftk.aspx?tk=B1462206-379C-42E1-AD4E-19A6F3149041&mail=250559

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80psi on the rear seems pretty universal
I would check with the manufacturer, Bailey told me 72 front and 80 rear, I would follow informed advice rather than people who want a soft ride, psi is stated for a reason.
Under inflated tyres will get too hot and a blow out in a moho, 3850kg at 70 mph would be quite scary and possibly fatal.
Ask your tyre supplier or vehicle builder for the correct advice and avoid the ill-informed who lower pressures and get a softer ride!
 
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I use the Moho quite a lot so I run my Michelin Agilis CP at 65psi on the 2250kg rear. The ride is fine compared to the 80psi recommended by Michelin. They hit about 80psi when warm so pretty close to the design 80psi when sat in a field for months on end. The rears have done 4 years and 40k now and are still like new with minimal wear and no cracking
 
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dunnah01 said:
This is pretty good for pressures based on actual axle weights

www.tyresafe.org

Motorhome Tyre Pressure Calculator | TyreSafe

Our motorhome tyre pressure calculator gives you the correct pressures for your motorhome. Check your tyres regularly for your safety.
www.tyresafe.org www.tyresafe.org
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From my direct communication with Continental's tech department, the recommendations differ hugely on the rear.
The front pressures are not that different - 53 PSI Tyresafe, 47 PSI Continental.

The rear pressures on my PVC (Autoquest CV20) suggested by TyreSafe, based on an accurate axle weight (weighbridge), is 80 PSI. Whereas the technical department at Continental suggest just under 50 PSI. Massive difference to ride if nothing else.

Taken from the TyreSafe website: "CP-type tyre construction enables the use of higher inflation pressures to provide resistance to the difficult conditions of use encountered on motorhomes. Therefore, when CP-type tyres are fitted on the rear axle in a single formation set the inflation pressures to 5.5 bar (80 psi) for all loads."

I'm not TELLING anybody anything here, except that I have gone with the tyre manufactures recommendations as opposed to (the generic?) Tyresafe ones.
If I am wrong, which is not unknown, could someone let me know soonest!
 
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Jo May said:
From my direct communication with Continental's tech department, the recommendations differ hugely on the rear.
The front pressures are not that different - 53 PSI Tyresafe, 47 PSI Continental.

The rear pressures on my PVC (Autoquest CV20) suggested by TyreSafe, based on an accurate axle weight (weighbridge), is 80 PSI. Whereas the technical department at Continental suggest just under 50 PSI. Massive difference to ride if nothing else.

Taken from the TyreSafe website: "CP-type tyre construction enables the use of higher inflation pressures to provide resistance to the difficult conditions of use encountered on motorhomes. Therefore, when CP-type tyres are fitted on the rear axle in a single formation set the inflation pressures to 5.5 bar (80 psi) for all loads."

I'm not TELLING anybody anything here, except that I have gone with the tyre manufactures recommendations as opposed to (the generic?) Tyresafe ones.
If I am wrong, which is not unknown, could someone let me know soonest!
Click to expand...
Some manufacturers follow the ETRMAs guidance of 80psi on rear CP tyres but some allow pressures for the equivalent van tyre. Tyresafe seem to go with ETRMA by default but if the manufacturers say different then go with them.

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HKF said:
Hi everyone

Here are the tyres and info I have on my MH. Can someone tell me what pressures they should be at, please? Our MH is rated at 3,500kg.

FRONT - Michelin Agilis Camping 215 / 70 R15 CP M+S 109Q at 80psi
REAR - Continental Van Contact Camper 215 / 70 R15 CP M+S Maximum inflation pressure single / dual 79psi 109R 475 KPA

Thank you so much :)
Click to expand...

60psi all round (easy to remember) is what I run my fully laden 3500kg Ducato.
I have not had any tyre problems in 8yrs. 👍
 
dunnah01 said:
I use the Moho quite a lot so I run my Michelin Agilis CP at 65psi on the 2250kg rear. The ride is fine compared to the 80psi recommended by Michelin. They hit about 80psi when warm so pretty close to the design 80psi when sat in a field for months on end. The rears have done 4 years and 40k now and are still like new with minimal wear and no cracking
Click to expand...
Do tyres inflated to 65psi cold really reach pressures close to 80psi when hot? I never thought the difference would be that much.

Every day's a school day!
 
L' Hobo said:
60psi all round (easy to remember) is what I run my fully laden 3500kg Ducato.
I have not had any tyre problems in 8yrs. 👍
Click to expand...
Similar. I run mine at 65 all round on 3.5t. However, I use the van regularly but if it looks like I'm not going to use it for a while and it's going to be standing, I pump them up to 80.
The van is 7.5yrs old, done about 30k and the tyres look new! But that's for another thread.🤭😂😂😂

Terry
 
Once you have determined the theoretically correct pressures for your van fully loaded and started using them, it's worth doing the touch test. As said somewhere above it's heat that damages tyres. The heat is normally generated by sidewall flexing. Too much flexing = too much heat. Too high a pressure = not enough heat (warmth) a hard ride and less grip. Just touch your tyres immediately after a long(ish) run. If the pressure are right for the van / load they should be comfortably warm. OAT will affect this and in constantly high temperatures you should increase the pressures slightly to discourage overheating.

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Last edited:
Dorset Diver said:
Once you have determined the theoretically correct pressures for your van fully loaded and started using them, it's worth doing the touch test. As said somewhere above it's heat that damages tyres. The heat is normally generated by sidewall flexing. Too much flexing = too much heat. Too high a pressure = not enough heat (warmth) a hard ride and less grip. Just touch your tyres immediately after a long(ish) run. If the pressure are right for the van / load they should be comfortably warm. OAT will affect this and in constantly high temperatures you should increase the pressures slightly to discourage overheating.
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OAT? :unsure:
 
Langtoftlad said:
This is the only valid piece of advice in your ill informed post
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I thought it was a useful post. By ‘the suppliers’ does this mean the tyre fitters - if so with respect they would not be my source of info over such an important piece of info. Personally I would use the manufacturer’s advice as they designed the tyres to a set of criteria.
 
ERTRO produced a one-size-fits-all 80psi pressure advice based on the idea that many motorhomers overload their vehicle and many motorhomers load their vehicles unevenly. Most motorhome manufacturers and some tyre manufacturers blindly accepted their advice. They mainly considered tyre failure (tread separation and blowouts) as this could bring litigation, and largely ignored contact-patch, skidding and stopping distance as these are all your fault if there is an accident where the tyres don’t physically fail. Not their fault. Ass-covering.
Some tyre manufactures considered that they would like their tyres to be used at the correct pressure for specific vehicles and wanted their tyres to have the best possible stopping distance and skid avoidance and thus get good reviews from users. If you provide accurate details, they will recommend pressures based on the technical construction of their tyres rather than one-size-fits-all. This means, of course, that you have to visit a weighbridge with a fully loaded vehicle.
Full fuel, Adblue and fresh water tank. Full black and grey waste tanks (With water!) Maximum case food and drink and passengers. If that’s too difficult then you have to accept the one-size-fits-all approach rather than just considering comfort. And accept the possible inferior handling and long-term coach work damage resulting from tyres that are at higher pressure than necessary. Some vehicle manufacturers even set these pressures in stone in their TPMS because “Big Brother Knows Best.”
 
Made enquiries with Michelin and Continental about the matter this morning. Had an interesting and extremely helpful conversation with Continental - contrast that with the useless one size fits all reply from Michelin (same as Panda posted above). So from Michelin - not interested at all in my axle weights just stated 5.5bar for the rear and check with MH manufacturer for the front. Useless. Continental gave me recommended pressures for the respective axle weights I advised them (1695Kg front and 1995Kg rear) for their new Vancontact Camper tyres (225/75 16 118) which was front 3.25bar and rear 4.25bar (they forwarded a chart for the relative axle weights for reference too). Quite a huge drop from my MH manufacturers, TyreSafe and ETRTO blanket figure of 5.5 bar for the rear and the MH manufacturers 5.5bar for the front! Basically Continental recognise that we aren't all daft enough to overload or unevenly load our MHs and a lot of us have got the common sense to make the effort to go to a weighbridge. I'll be ditching my nearly new Agilis (if anybody wants to make me an offer) and getting some Continentals. In fact I also have Michelin on our car and a motorbike so Michelin have lost a bit of custom.

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Continental publish a handbook of tyre pressures for each model, size, load rating and axle loading.
 
Easy enough to guesstimate really, axle load/(load ratingx2) x max pressure so using the figures above 118 load rating=1320kg so per axle is 2640kg, the calculation would be for front 1695/2640=0.642 x max pressure (80psi usually) = 3.54bar vs 3.25 from Continental so close enough for me, the rear calc 1996/2640=0.756x80=60.48 or 4.17 bar so again very close as in within 1.5psi so close enough for me (y)

The load rating figure in kg is easily found on the web and just x2 for the axle.
 
Hi funfair. You calculation method may be interesting but surely it is not something to rely upon. I am concerned with being able to convince the police / insurance (should the need arise) that my tyre pressures are correct even though they may be lower than the vehicle manufacturer has specified. Michelin have been as much use as a chocolate ashtray - if I continue with Michelin I feel I have no alternative but to run the suggested ridiculously high pressures (and loose my teeth), I wouldn't have a leg to stand on if there is ever a reason to dispute why my tyres were inflated below the vehicle manufacturers guidelines AND the tyre manufacturers guidelines. However, with Continental I can now refer police / insurance company to an email and Continental's chart to illustrate that for my vehicle running with the axle weights I use I have inflated my tyres to the correct pressure recommended by the tyre manufacturer.
 
I can't believe that, with something as vital as correct tyre pressure, the figures we need aren't easier to find. I remain totally confused as to what my 'correct' pressures should be and can only guess at what might be acceptable, based on a third party website's calculator. Are people really expected to contact the manufacturer of both the tyres and the MH in order to get the right numbers? And, what happens if those numbers aren't the same from both sources?
 
HKF said:
I can't believe that, with something as vital as correct tyre pressure, the figures we need aren't easier to find. I remain totally confused as to what my 'correct' pressures should be and can only guess at what might be acceptable, based on a third party website's calculator. Are people really expected to contact the manufacturer of both the tyres and the MH in order to get the right numbers? And, what happens if those numbers aren't the same from both sources?
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It's because they are coachbuilt, with more than one manufacturer.

On a PVC I expect you get a sticker, like you have on your car, with wheel/tyre sizes and pressures. There is one on my VW, but that started off as a delivery van.

Really, the motorhome manufacturer should be providing this information.

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