Tyre pressure

I have just bought of flea bay 4 mud snow winter tyres as most of the year here is wet cold and roads covered in farmers slurry droppings, I think. :eek: 😂
 
Only guessing, but Michelin probably don't want a lawsuit resulting from an accident involving a heavily overloaded van with their "calculated" rear axle tyre pressure, so they play safe, I don't blame them.
What I still can't understand is if CP rated tyres have to run at 80psi, why can their normal commercial tyres run at lower pressures with the same axle load despite being "less reinforced" ....... we all use the same "pot holed" roads 🤔😄 Answers on a postcard please!
 
trevskoda said:
I have just bought of flea bay 4 mud snow winter tyres as most of the year here is wet cold and roads covered in farmers slurry droppings, I think. :eek: 😂
Click to expand...
I won't be the farmers droppings ;) unless he is a Motorhomer as well of course, in which case he will be flinging it everywhere (think I read that in the BallyCastle Daily Mail?)
 
Rear wheel drive on a Sprinter, 3500 kg. Michelin Agilis CP 225/70/R15C 112, with 55 front and 65 rear, comfortable.
Tried the recommended 82 psi and very uncomfortable and noisy. I use the TyreSafe graph and adjust
the pressures if any major changes before going away.
 
Val54 said:
Don't think so, I get the same page and options.

I have to say I get confused by this site, they state ....

If the ‘standing a long time’ argument held water surely it would apply to the more heavily loaded front tyres also. Given that when my van is standing a long time it is unloaded, and the rears wheels accordingly loaded even lighter still than the front which continue to carry engine gearbox and fuel tank.

"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."

However, I'm not sure what they mean by "difficult conditions of use". I have CP rated tyres fitted so obviously get a result of 80psi on the rear axle, if I change the rating to "C" with the same tyre size and axle load I can drop the pressure to 59psi. 🤔🤔
Click to expand...
 
Once my camper tyres are worn out I’ll be replacing with all-season m+s 3 Peak ones. Unfortunately when I bought it I couldn’t persuade the dealer to supply it with these, and I can’t persuade myself to spend £5-600 on another set and flog the CPs off at a great loss.
 
barge1914 said:
Once my camper tyres are worn out I’ll be replacing with all-season m+s 3 Peak ones. Unfortunately when I bought it I couldn’t persuade the dealer to supply it with these, and I can’t persuade myself to spend £5-600 on another set and flog the CPs off at a great loss.
Click to expand...
And if they are Michelin CrossClimate they will tell you not for use on Motorhomes, been there, done that, phone conversation.
 
Fisherman said:
Apologies for bringing up a subject discussed many times on here.
I have mitchelin agilis tyres which I run at 65psi.
My van is a 3.5T ducato a class.
But once warmed up after a few miles they rise to around 72psi.
Reading some posts on here I may be running a bit under pressure.
Any opinions on this.

Thanks in advance.
Click to expand...
Your tyre pressure will rise after a run due to heating of the rubber. I think tyres should be inflated when cool As they are cool when fitted then blown to correct pressure. I keep mine at 65 and check before trip rather than on trip.
 
mark61 said:
Michelin USA don't have any problem promoting the Agilis CrossClimate for RV's.
It is possible it's not the same tyre of course.
Important to include the model name Agilis.

https://www.michelinrvtires.com/tir...NlIWZhbHNlIWZhbHNlIXNlbGVjdG9ybmFtZSFaITEwITE
Click to expand...
This is the specific tyre I asked about.
www.blackcircles.com

Michelin Agilis CrossClimate 215/75 R16 R tyres | Blackcircles.com

Buy tyres online and get them fitted locally with Blackcircles. Lifetime Guarantee now on all car, van & SUV tyres. Peace of mind, at no extra cost.
www.blackcircles.com
As with all tyres in this size there is no CP tyre which is up to the job for our van.
 
colinm said:
This is the specific tyre I asked about.
www.blackcircles.com

Michelin Agilis CrossClimate 215/75 R16 R tyres | Blackcircles.com

Buy tyres online and get them fitted locally with Blackcircles. Lifetime Guarantee now on all car, van & SUV tyres. Peace of mind, at no extra cost.
www.blackcircles.com
As with all tyres in this size there is no CP tyre which is up to the job for our van.
Click to expand...
Would the rims not take 225 width instead? I seem to remember there is a bit of flexibility in the tyre width fitting from my youthful motoring days ............
 
Val54 said:
Would the rims not take 225 width instead? I seem to remember there is a bit of flexibility in the tyre width fitting from my youthful motoring days ............
Click to expand...
They would, but I was interested as to what Michelin would say, it was obvious that it was a case of "Computor says", as the person answering said I should use CP tyres, when I pointed out these where not rated to the axle load they gave up and said they didn't have a suitable tyre to offer, as it happens the van came from Globecar with Conti's fitted, in this size they are marked as C, but are built as a 10ply CP tyre, there are thousands of PVC's where the base vehicle is supplied by Fiat to large convertors with C tyres.
 
Filled 100% with Fresh Water and put bike on rear rack and paid a visit to the local weighbridge so I could then check pressures on the tyresafe site ....


Currently got 2120Kg on the Rear and 1520Kg on the front, giving me 210Kg payload left, so not too bad - except weights don't include any people. But reckon two people and a full fuel tank (currently half full) would still see us under the limit. And could easily travel with the fresh tank only half-full if need be.

Put in weight to take to 3850Kg, with the rear axle at the limit as well as adding all the spare payload plus a bit more at the front end up with this:

1630428957954.png

Surprisingly low on the front and a bit lower than I would have expected at the back

Checked the pressures when I got back home (total distance from home to WB to home again was maybe 8 miles?)
1630429180712.png

Will check the pressures from "proper" cold in the morning, but looks like I could reduce the fronts and check (even out at least) the rears - I don't think ~22C is the tyres warmed up very much so pressure is likely 65PSI (what I originally set in fact).
 
edit: I thought I was replying to a previous post but the quote didn't come up. So forget it. I just use the pressures on the door post label, I don't see anything wrong with that.
Oh and by the way did you know that if you have a new - ish motorhome with a TPMS then it has to be working properly for the MOT? Reason number two thousand nine hundred and eighty six not to buy a new motorhome.
 
gasgas said:
I just use the pressures on the door post label, I don't see anything wrong with that.
Click to expand...
Our van, like many others, is built on a Maxi chassis but only licenced for 3.5t. The door pillar pressures are for axle loads which add up to 4.5t, considerably higher than we can legally use, let alone those we actually run at.
 
If the tyre wears even across the tread then the psi you are running is correct, 5 or so psi either way wont make a blind bit of differance.
 
You must log in or register to reply here.

Users who viewed this discussion (Total:0)

Back
Top