New TyreSafe MH website page

[Keithl]

I have just been on the Tyresafe website to answer another forum members query on tyre pressures to find it had a major makeover earlier in August this year.

 

No longer does it give you the downloadable table of tyre pressures against axle loads but now has a very convenient ready reckoner style table where you input axle loads, pick the correct tyre size from a drop down menu and then it calculates your tyre pressures for you.

 

https://www.tyresafe.org/check-your-pressures/motorhomes/

 

What is very interesting is if you are near the axle load limits with 'C' tyres it adds a 'recommendation' to use CP tyres with the following warning :

 

"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."

 

In other words they are now following 'Industry standard' in recommending 80 psi for CP Rears irrespective of load.

 

Thought you all might like to be aware of the change.

 

Keith.

[Brock]

Thanks Keith. Having reduced mine to 5.25bar for a better ride recently, I'll have yo get the pump out again.

[Derek Uzzell]

As has been said on this forum several times before, the 5.5bar pressure advice for CP-marked tyres fitted to a motorhome’s ‘single wheel’ rear axle comes from an ETRTO stipulation (see page 46 of following link)

 

http://www.pneusnews.it/wp-content/uploads/2013/08/ETRTO-RECOMMENDATIONS-EDITION-25-SEPTEMBRE-2014.pdf

 

The advice takes no account of a motorhome’s specification, weight, axle-loadings, tye-size, or even how many rear axles it has - if it has CP-marked tyres on the rear axle, according to the ETRTO these MUST be inflated to 5.5bar/80psi.

 

There’s a long history to this magic 5.5bar inflation-pressure, going right back to when Michelin started marketing the XC Camping pattern. I very much doubt there are any credible statistics to support the ETRTO’s insistence on 5.5bar and it’s surprising it has not been challenged.