Tyre Pressures

[Iain55]

Hi all,
I am a newbie to motorhomes, got mine last August. I have not check my tyre pressures since I bought the vehicle.
They were all exactly 0.9 BAR below the sticker on the door.
I checked on the internet that seems correct for a Renault Master van.
However the sticker on the door says 4.5 and 5.5. My motorhome is 3.85 T (over 4 when fully laden)
In your experience does the door sticker seem correct ?

 

[Beemer]

It is worth going into the search panel as this topic has been covered a few times.
Some members on here think that manufacturers written pressures are wrong and pressures should be lower that stated.
I have tried to adhere to manufacturers TPs since owning my A class (4.5T) the last 6 years, pressures are stated as 5.5bar all round (tag axle) even though 80psi seems high.
I have tried 65psi in the hope that maybe it would prove to be a softer ride, but in my mind made no difference, so they are back up to 5.5bar.
The advantage of having a tag axle was evident when I had a puncture on one of the tyres on the middle axle, it made very little difference to the handling of the vehicle and I was able to still drive (sensibly) to a safe area where I could change the wheel.

 

[cronkle]

The two main schools of thought are to either go by the vehicle manufacturer's pressures on the door pillar or to go to a weighbridge, weigh each axle and then go by the tyre manufacturers recommended pressures.

This is a good guide https://www.tyresafe.org/wp-content/uploads/2015/12/motorhome-leaflet.pdf. and if you have Continental tyres they produce their own booklet which is available on line. You could also email the tyre manufacturers with your tyre size and weights and they will usually reply with the appropriate figures. However, Michelin will always tell you that your rear axle must be at 80psi.

I prefer to go with the tyre manufacturers recommendations.

 

[wildebus]

On most vehicles there are is a Tyre Pressure chart on a door jamb or similar - and the key thing is that there are usually 2 or 3 different ranges based on the vehicle load - and the heavier the load the greater the pressure.
I can't really see that logic suddenly going out the window just because there is only one set of figures on a door sticker. More than likely they have done that based on the vehicle being used to its full capacity and assuming the driver will not bother to ever adjust, so to me it would make sense that if you are significantly lower in weight, the tyres should be a lower pressure.

As far as using a pressure based on a tyre makers numbers rather than a vehicle makers - who knows what would suit that specific vehicle better?
Is it the company that makes the vehicle and provides legal guidence for pressures irresepective of which brand tyre is fitted? or a Tyre Manufacturer who makes a tyre that is sold for and goes on dozens and dozens of different vehicles of different configuations?

I use some logic and not blindly go with a set value. I'm running 65PSI all round on my 4.6t van that is running at around 3.75t in running order on its Michelin Tyres.

 

[Wooie1958]

Hi all,
I am a newbie to motorhomes, My motorhome is 3.85 T (over 4 when fully laden)

I don`t understand what you are saying about the weight of your motorhome.

If it is 3.85 T ( a common GVW for motorhomes ) then you are running overweight when you say " over 4 when fully laden. )

If it is indeed over 4 GVW then what is the 3.85 T you mention ?

 

[cronkle]

Tyre pressure table

Unfortunately whatever weight you put on the rear axle it always comes up with 5.5.bar. This is at odds with the pdf. that I posted a link to earlier - same organisation. However the pdf. gives values very similar to those on the Continental pressure chart. https://blobs.continental-tires.com...560e449f/download-technical-databook-data.pdf from about page 76 onwards.

 

[Obanboy666]

Just looked up the CI Cipro 85 and the MTPLM is indeed 3850kg with a payload of 895kg so If iain55 is running at over 4000kg he is carrying approx 1000kg of payload ! Hope he has updated the MTPLM.

 

[RoaminRog]

My Motorhome is also based on a Renault Master, I recently replaced the tyres all round with Continentals Four Seasons.
Eager to look after my new purchase, I rang Continental Technical Dept for advice after weighing my axle weights.
They advised 55psi front and 66 psi rear.
I find we get good handling and a very comfortable ride. Hope this helps.
Incidentally, if your plate says 3850kg, that’s it, max weight 3850kg. If you are running at over four tonnes, you are overweight, and could possibly get nicked.

 

[trevskoda]

Im running 60psi all round on 226/75r/16c on a 4.3 ton bus with double back wheels.

 

[Iain55]

My Motorhome is also based on a Renault Master, I recently replaced the tyres all round with Continentals Four Seasons.
Eager to look after my new purchase, I rang Continental Technical Dept for advice after weighing my axle weights.
They advised 55psi front and 66 psi rear.
I find we get good handling and a very comfortable ride. Hope this helps.
Incidentally, if your plate says 3850kg, that’s it, max weight 3850kg. If you are running at over four tonnes, you are overweight, and could possibly get nicked.

Thanks, I'll double check my weights

 

[Iain55]

My Motorhome is also based on a Renault Master, I recently replaced the tyres all round with Continentals Four Seasons.
Eager to look after my new purchase, I rang Continental Technical Dept for advice after weighing my axle weights.
They advised 55psi front and 66 psi rear.
I find we get good handling and a very comfortable ride. Hope this helps.
Incidentally, if your plate says 3850kg, that’s it, max weight 3850kg. If you are running at over four tonnes, you are overweight, and could possibly get nicked.

As I said i am new to motorhomes. I was only repeating what I was told, however I will check my weights now, thanks

 

[Iain55]

Just looked up the CI Cipro 85 and the MTPLM is indeed 3850kg with a payload of 895kg so If iain55 is running at over 4000kg he is carrying approx 1000kg of payload ! Hope he has updated the MTPLM.

As I said, I am new to motorhomes, will check weights, thanks.

 

[Iain55]

I don`t understand what you are saying about the weight of your motorhome.

If it is 3.85 T ( a common GVW for motorhomes ) then you are running overweight when you say " over 4 when fully laden. )

If it is indeed over 4 GVW then what is the 3.85 T you mention ?

As I have said I am new to motorhomes and repeated what I was told, will check weight and plate, thanks.

 

[Molly 3]

I was told by my supplying dealer . To use the pressure stated on my door post, so that is what I do .the tyre manufacturer ,Continental, recommend a lower pressure . I assume the manufacturer's TP covers a van up to max plated weight . I must run very close to when running with full tanks etc . your choice which you choose .

 

[Iain55]

I was told by my supplying dealer . To use the pressure stated on my door post, so that is what I do .the tyre manufacturer ,Continental, recommend a lower pressure . I assume the manufacturer's TP covers a van up to max plated weight . I must run very close to when running with full ranks etc . your choice which you choose .

I've always used the door post pressures on my cars, I kind of feel uncomfortable ignoring something which is there in black on white. I also did wince at the higher pressures

 

[Molly 3]

Im running 60psi all round on 226/75r/16c on a 4.3 ton bus with double back wheels.

I run my push bike at 60 psi .don't expect that helps either .lol

 

[Iain55]

I run my push bike at 60 psi .don't expect that helps either .lol

The door post label says 4.5 front 5.5 bar back that's 65 and 80 psi

 

[Molly 3]

That is what I would use .

 

[RoaminRog]

The door post label says 4.5 front 5.5 bar back that's 65 and 80 psi

Try it, you can always let them down again if you’re not happy.
When we had our Hymer, Michelin recommended 80 psi on the rear, and the result was a very hard and uncomfortable ride, not to mention noisey.
If the pressure in the front is too high, you will notice the steering being too light and loss of control in a cross wind.

 

[Beemer]

Copied from another Motorhome site

From:
MICHELIN Customer Service,
...
Regarding your query, we only have the pressure recommendation for our MICHELIN Agilis Camping.
The pressure recommendation for the rear (single) axle of a motor-home running on the MICHELIN Agilis Camping is 80 PSI. This is due to the construction of the tyre with 2 casing plies enabling the use of higher pressures.
It’s construction and the use of higher pressures is designed to cope with continual heavy loads sometimes found on motor-homes and can help with wear pattern issues, if lower pressures are used particularly on the rear axle.
The front tyres however can be adjusted down to a pressure of 65 PSI for a more comfortable ride and optimum performance.
Here are some safety points to be taken into account when it comes to tyre pressures:
1. 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.
2. When the tyres are hot you should always add 4,4 PSI to the recommended pressure.
3. Please remember - Never deflate a hot tyre!
I hope this information was helpful and please do not hesitate to contact us again if you have any further questions or concerns. We are happy to help.
Kind regards,Dora
MICHELIN Customer Care
Passenger Car & Light Truck Tyres