Tyre pressures

[Otter Spotter]

Since converting my Citroen Relay van to a motorhome, I am wondering whether the tyre pressures should be altered to reflect the fact that it is carrying constant weight as apposed to a panel van where loads will very each day.
What should I be doing? I have just bought a set of TyrePal monitors discounted courtesy of the funster discount.

 

[Pete5996]

One option would be to get the vehicle, when loaded to your normal travelling weight, to a weighbridge (yes, I appreciate the difficulties at present), get each axle weighed and then contact the tyre manufacturer for their recommendation.

 

[funflair]

You need to weigh it individually both axles, you can then work out the pressure related to your tyre.

Martin

 

[Jev88]

I found this also helps once you have weights.

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

 

[bigwood]

A friend of mine had this same issue and after checking his weights contacted Continental. They advised him of the correct tyre pressures.
Tyres on the drive fitted the tyres to our van. The fitter already knew the pressures because he had been to the same van conversion recently.

^{_{Subscribers  do not see these advertisements}}

 

[Otter Spotter]

Thanks guys, I will try and get the van weighed ASAP

 

[JohnJan]

Is it a 6.35m Relay? If so, I run at the given 5.5 bar(79.5psi) which came from the plate on the van. Tyres are Continental VancoCampers 225/75-16

 

[Pete5996]

Is it a 6.35m Relay? If so, I run at the given 5.5 bar(79.5psi) which came from the plate on the van. Tyres are Continental VancoCampers 225/75-16
View attachment 379420

Probably far too high, tbh. I run Vancocampers 225/75-16 and I contacted Continental with the following information:
Front axle 1600kg
Rear axle 2040kg
Total weight 3680kg

Their reply was:

Hello Peter,
Pressures Are:
Front: 3.0bar
Rear: 4.5bar

Set to those pressures, at motorway speeds in hot weather, my TPMS shows the fronts increasing up to about 4.0bar and the rears increasing to up to 5.5bar. There is a table somewhere which shows all the pressures v weight for the 225/75-16 but I can't find it....

 

[JohnJan]

Probably far too high, tbh. I run Vancocampers 225/75-16 and I contacted Continental with the following information:
Front axle 1600kg
Rear axle 2040kg
Total weight 3680kg

Their reply was:

Hello Peter,
Pressures Are:
Front: 3.0bar
Rear: 4.5bar

My question would be why is there a plate on the van with tyre pressures if they are not correct and accurate? I don't doubt you know more about this than me but please enlighten me

 

[Pete5996]

My question would be why is there a plate on the van with tyre pressures if they are not correct and accurate? I don't doubt you know more about this than me but please enlighten me

Don't bank on it!? I have the same plate on my Ducato and I can only assume it's applied at the factory to cover all eventualities - I've no doubt someone else can explain why the plate is a standard fitting.

^{_{Subscribers  do not see these advertisements}}

 

[Speve]

My take on the pressures on the plate is they are for when you are at maximum load for that vehicle?
in most camper and Motorhomes they would most likely be very close to max weight??

 

[Pete5996]

My take on the pressures on the plate is they are for when you are at maximum load for that vehicle?
in most camper and Motorhomes they would most likely be very close to max weight??

The thing is, that is at variance with the information provided by the tyre manufacturer, who specified the pressure required for the actual load on each axle. One has to assume they know their product?

 

[Speve]

I would tend to agree however if you go to Michelin they invariably just quote max pressure.

 

[Pete5996]

I would tend to agree however if you go to Michelin they invariably just quote max pressure.

Yes, I've noticed that. Whether the manufacturers' tyre construction differs I don't know, so who is to say which is correct?

 

[JohnJan]

Even more confused now!

Bring back solid rubber, that's what we need!!

^{_{Subscribers  do not see these advertisements}}

 

[bigwood]

If its any guide the tyre pressures for our Rienza as per the data plate made it a very hard ride. It is based on a Transit 300 chassis. After a bit of trial and error we now run 55 front 65 rear (3.4-4.8 bar) as per Continentals advice. We are way below the maxi load even with a full tank of water and supplies for about two weeks.
The Continentals are a harder ride than the Michelins to start with so you really feel the difference if you over inflate.

 

[Otter Spotter]

Hi guys I have used the tyresafe website calculator and that says 49 front 48 rear based on weighbridge weights which managed to get this morning. The vehicle tyre plate says 59 front 65 rear so I have emailed continental for clarity.
i will let you know what their answer is

 

[Otter Spotter]

Hi guys I have used the tyresafe website calculator and that says 49 front 48 rear based on weighbridge weights which managed to get this morning. The vehicle tyre plate says 59 front 65 rear so I have emailed continental for clarity.
i will let you know what their answer is

 

[funflair]

Hi guys I have used the tyresafe website calculator and that says 49 front 48 rear based on weighbridge weights which managed to get this morning. The vehicle tyre plate says 59 front 65 rear so I have emailed continental for clarity.
i will let you know what their answer is

You should find your tyres down at pages 86-87

https://blobs.continental-tires.com/www8/servlet/blob/585550/e0854f2c7866c64da551474b998ef8b3/download-technical-databook-data.pdf

Martin