I’ve been in touch with Continental to ascertain the appropriate tyre pressures related to the axle loadings from my recent weighbridge visit.
The response was both rapid and very helpful so I thought it would be worth sharing an extract from the email I received.
Is interesting, despite having accurate loads, that the ETRTO, as noted in the response, recommend inflating the rear tyres to a minimum of 5.5bar (79 psi) on a “just in case you might be overloaded basis”.
Extract
You should be able to work it out via the extract from our technical data book for your tyre pressure recommendations at certain axle weights below.
I’d highly recommend going to a weighbridge with the vehicle under normal laden conditions (water tank, fuel, bikes, food, etc) to get the specific front and rear axle weights you would be using the vehicle at. And it is from these weights that the tyre pressure guidance can be used.
Based on the 225/75 R16 CP 118R the inflation pressure guidance is:
I have also attached the page from the technical data book showing the various pressures at various weights fyi.
I have highlighted the info you should refer to in yellow and then look at the top of the page for the inflation pressure in bar.
Also, you need to know that,
FA S means Front axle single fitment.
RA S means Rear axle single fitment.
RA T means Rear axle with twin tyre fitment.
There are some variations in pressures given from different sources. The reason for the confusion and higher pressure from some sources on the rear is because the ETRTO (European Tyre & Rim Technical Organisation) in their standards manual have a paragraph that suggests all CP type tyres fitted as single fitment rear tyres on a camper should be inflated to a minimum of 5.5 bar (79 psi), even if the load on the axle is such that the inflation requirement based on the standard ETRTO tables and manufacturer data is lower. This advice is because of the likelihood of overloading or uneven load distribution in camper applications and the need to compensate for this with a higher inflation pressure.
Our current stance remains unchanged when calculating recommended pressures which is directly calculated from the given loads provided by yourself against the pressure recommendations in the technical data book and this is the information we provide.
However, given the information in the ETRTO manual we give this pressure as a guide and should only be used on the understanding that no single tyre will be overloaded, and the axle loads given will not be exceeded.
If you have any questions, please do not hesitate to call or email.
Thank you.
Kind Regards,
Robert Hughes
Warranty and Technical Administration Team
Visitors Address:
Technical Customer Service
Continental Tyre Group Ltd
1st Floor Building DC 2
Castle Mound Way
Central Park
Rugby
CV23 0WB
Office Line: +44 (0)1788 566240
Fax: +44 (0)1788 517731
E-Mail: administrator.technical@conti.de
Web: http:// www.continental-tyres.co.uk
The response was both rapid and very helpful so I thought it would be worth sharing an extract from the email I received.
Is interesting, despite having accurate loads, that the ETRTO, as noted in the response, recommend inflating the rear tyres to a minimum of 5.5bar (79 psi) on a “just in case you might be overloaded basis”.
Extract
You should be able to work it out via the extract from our technical data book for your tyre pressure recommendations at certain axle weights below.
I’d highly recommend going to a weighbridge with the vehicle under normal laden conditions (water tank, fuel, bikes, food, etc) to get the specific front and rear axle weights you would be using the vehicle at. And it is from these weights that the tyre pressure guidance can be used.
Based on the 225/75 R16 CP 118R the inflation pressure guidance is:
I have also attached the page from the technical data book showing the various pressures at various weights fyi.
I have highlighted the info you should refer to in yellow and then look at the top of the page for the inflation pressure in bar.
Also, you need to know that,
FA S means Front axle single fitment.
RA S means Rear axle single fitment.
RA T means Rear axle with twin tyre fitment.
There are some variations in pressures given from different sources. The reason for the confusion and higher pressure from some sources on the rear is because the ETRTO (European Tyre & Rim Technical Organisation) in their standards manual have a paragraph that suggests all CP type tyres fitted as single fitment rear tyres on a camper should be inflated to a minimum of 5.5 bar (79 psi), even if the load on the axle is such that the inflation requirement based on the standard ETRTO tables and manufacturer data is lower. This advice is because of the likelihood of overloading or uneven load distribution in camper applications and the need to compensate for this with a higher inflation pressure.
Our current stance remains unchanged when calculating recommended pressures which is directly calculated from the given loads provided by yourself against the pressure recommendations in the technical data book and this is the information we provide.
However, given the information in the ETRTO manual we give this pressure as a guide and should only be used on the understanding that no single tyre will be overloaded, and the axle loads given will not be exceeded.
If you have any questions, please do not hesitate to call or email.
Thank you.
Kind Regards,
Robert Hughes
Warranty and Technical Administration Team
Visitors Address:
Technical Customer Service
Continental Tyre Group Ltd
1st Floor Building DC 2
Castle Mound Way
Central Park
Rugby
CV23 0WB
Office Line: +44 (0)1788 566240
Fax: +44 (0)1788 517731
E-Mail: administrator.technical@conti.de
Web: http:// www.continental-tyres.co.uk
