Postscript on fitting Michelin Cross Climate Campers to my Rapido 8094DF - tyre pressures

[LittleGreyCat]

Michelin Cross Climate Camper 215/70 R15 R.
Had them fitted today.
Branch manager commented that they were a very aggressive tyre.
They do have a very different (sided) tread pattern from the Continental tyres which came off.
They in fact have an almost identical tread pattern to the 4 season tyres on my VW Touareg 4x4 (aimed at pulling a caravan off a muddy field before we swapped the caravan for the MH).

I now have to find a wet field to try them out in (although not too wet and muddy for the first attempt).

On the subject of tyre pressures, I was told that the maximum pressure for the tyres was lower than the pressures shown inside the front door of the MH.
That is 5 bar/72.5 PSI front and 5.5 bar/79.8 PSI back.

I am now in the process of chasing up Michelin to get their advice.

I think I will be going down the route of weigh bridge for each axle then a recommendation from Michelin.

 

[LittleGreyCat]

Reply from Michelin (which will raise a few eyebrows!).
Apparently you should ignore the markings on the tyre!

Regarding your inquiry about the appropriate tyre pressures for your Michelin CrossClimate Camping tyres, the recommendation is as follows (even though stated otherwise on the tyre, the recommendation bellow is what you should refer to):• On the rear axle: the motorhome tyre pressure should be 5.5 bar (80 psi). The maximum load capacity of the tyre must be respected. (Note that the use of a metal clamp in valve or specific high pressure rubber valve is required above 4.5 bar (65 psi)),• On the front axle: refer to the manufacturer's inflation recommendations indicated on the vehicle and / or its handbook. You can find the manufacturer´s recommended pressures in the vehicle´s technical document, on the side of the driver’s door or inside the fuel tank lid.

 

[Just smiffy]

It’s been known for years on here that Michelin always state 80psi on all there tyres whatever the weight…
If you want to rattle your teeth out then carry on but most will adjust the pressures to there liking, continental will give you precise pressures for their tyres if anyone emails them with the weights of their vehicle….

I think the average most people do are 55-60psi fronts 65-70 rears… but it’s whatever brings the best results and driving comfortable by trial and error…

 

[LittleGreyCat]

They key point is this:
(Note that the use of a metal clamp in valve or specific high pressure rubber valve is required above 4.5 bar (65 psi))
So for 65-70 rears you need a high pressure valve fitted.
I haven't got down and dirty to read the sidewalls, but I am waiting on the tyre fitter to confirm that high pressure valves were fitted.
If not I can't safely follow the pressures you suggest.

 

[dunnah01]

They key point is this:
(Note that the use of a metal clamp in valve or specific high pressure rubber valve is required above 4.5 bar (65 psi))
So for 65-70 rears you need a high pressure valve fitted.
I haven't got down and dirty to read the sidewalls, but I am waiting on the tyre fitter to confirm that high pressure valves were fitted.
If not I can't safely follow the pressures you suggest.

The tyrewall won't show the max pressure for the UK although it may have a value for the Canadian market. Your tyre fitter should have known that they would need at least the high pressure rubber valve fitted so poke him in the eye if only regular car valves have been fitted.

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[LittleGreyCat]

The tyrewall won't show the max pressure for the UK although it may have a value for the Canadian market. Your tyre fitter should have known that they would need at least the high pressure rubber valve fitted so poke him in the eye if only regular car valves have been fitted.

"There are markings on the sidewall of the tyre (MAXLOAD and MAX PRESS) that indicate the maximum load and the maximum pressure of the tyre. However, these are not necessarily the load and pressure values for your vehicle.
To ensure that your tyres perform correctly on your vehicle, you must refer to the inflation pressures recommended by the manufacturer of your vehicle. These can normally be found in your owner's manual or on the sticker in the driver's door or fuel filler cap."
This from Michelin UK.
So I am not sure where you get your information that tyres for the UK market will not show maximum pressure.
Do you have a reference, please?

 

[LittleGreyCat]

Confirmed that the wheels have metal clamp valves and they just replaced the core.
Which I didn't even know was a thing.
Every day a school day.

Anyway, the valves are good for 5.5 bar so I can safely experiment.

 

[gus-lopez]

When i run at 3500kgs the pressures are 55psi front & back. the front tyres have done 60,000kms & the rears far more as they were on it when I bought it 4 years ago & I think now are 6 years old?

 

[stevewagner]

I find the Tyresafe website the best for finding the correct tyre pressures.

 

[Jev88]

I find the Tyresafe website the best for finding the correct tyre pressures.

Yes. www tyresafe.org is very useful if you have weighbridge axle weights

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[Chrisvh]

Thanks. Very useful post.

 

[Stroppy Bird]

Out of interest, what is the max pressure stated on the tyrewall?

 

[LittleGreyCat]

Out of interest, what is the max pressure stated on the tyrewall?

I haven't been able to find it so far.
The tyre wall is covered in small print and I'd have to get down and dirty in work clothes to get a close look.
I think is was around mid sixties PSI so around 4.5 bar.
I will have a look in the next few days.

 

[TheMachMan]

Just thought I’d raise this rather than start another. Just had these fitted and inflated to 65psi which according to the fitter is their max rating. So I don’t understand why I would increase the pressure above this to match the figures on the door frame sticker? Surely if I go over the tyre rating that’s a bad thing?

 

[Barriesimpson]

When i run at 3500kgs the pressures are 55psi front & back. the front tyres have done 60,000kms & the rears far more as they were on it when I bought it 4 years ago & I think now are 6 years old?

I run front and back at 4 bar (58 psi). Drive is fine.

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[Al n Val]

I run with 65 front and 68psi on both rear axels

The ride especially at the front end is transformed, no more crash banging coming up through the steering column

I love ‘em

 

[TheMachMan]

I run with 65 front and 68psi on both rear axels

The ride especially at the front end is transformed, no more crash banging coming up through the steering column

I love ‘em

I agree that the ride is considerably better. Really don’t want to go any higher, but at the same time I am a rule follower!

 

[enark]

I run a 4000kg Rapido on Michelin tyres and tried varying pressures.

Settled on 65psi for the front and 72psi for the rears…

Think the Michelin recommendation is for 80psi, but that gets a bit trying, especially on the M6 elevated section through Birmingham (concrete strip)….

 

[cyberyacht]

I've been running my cross climates at 70psi on the back.

 

[LittleGreyCat]

Just thought I’d raise this rather than start another. Just had these fitted and inflated to 65psi which according to the fitter is their max rating. So I don’t understand why I would increase the pressure above this to match the figures on the door frame sticker? Surely if I go over the tyre rating that’s a bad thing?

As stated up top, the recommendation from the tyre manufacturer is to ignore the sidewall markings and follow the advice from the converter.
I assume that means there is some leeway in the safe pressure above the tyre wall markings.
The markings are not for the UK market.
No idea why they are that low.

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[TheMachMan]

As stated up top, the recommendation from the tyre manufacturer is to ignore the sidewall markings and follow the advice from the converter.
I assume that means there is some leeway in the safe pressure above the tyre wall markings.
The markings are not for the UK market.
No idea why they are that low.

Cheers, seems bizarre that the pressure stated on the tyre itself can be ignored and follow the recommendations of a converter. What makes them more qualified to advise, compared to the original manufacturer??