Tyres? Yes, sorry, yet another post about tyre choice ;-)

[Dean14]

Ok, Ok - I know this topic has been posted about on numerous occasions so do apologise but I am seeking advise regarding improving the ride (to make it less crashy and harsh) in our McLouis 373. After much reading I have almost certainly narrowed my choice and specifically ask can anyone that may have changed from Michelin Agilis Campers (run at Michelin's crazy recommended pressures) to Continental VanContact Campers (run at Continental's much lower recommended pressures) post their opinion? Has it improved the ride or made little or no difference?
The MH is only 3 old and tyres have done under 2k miles but I'm prepared to pay for newer tyres if they do actually make a difference, hence my post. I have already had VB semi-air fitted to rear axle and uprated coils on the front. I have read hundreds of posts about the matter and appreciate that switching to C (instead of CP) tyres would probably give a better ride but if I ever need to explain my tyre choice to my insurance company (or the police) then personally I'd prefer to be able to point them to the actual tyre manufacturers' recommendations - and in correspondence with Continental they have recommended camper tyres for MHs. I also appreciate that full air would probably be better - but that's out of budget.
Thanks for any input.

 

[peterc10]

My Hymer does not have a visible plate showing recommended tyre pressures, as cars do. I used to have Continental CP tyres and carried in my motorhome a print out of Continental's advice as to tyre pressures for axle weights.

Now I have changed to Falkens C tyres I carry a print out from Falken's website for tyre pressures for axle weights of C class tyres. At the top of that sheet it clearly shows that the information is for motorhomes as well as a range of commercial vehicles. I cannot see how anybody could possibly argue that my tyres or their pressures are not suitable, given that I am using the information from the best source, i.e. the maker of the tyres.

 

[peterc10]

I’ve also been wondering about the TPMS system on the 2024 Fiat Ducato and whether it can be reset to a lower target pressure than 80psi?

Good question, and one I had to sort out on my Continental CPs. The parameters can be changed by accessing the information from the OBD port with dedicated software. That was way past my pay grade but luckily my son had a pc and leads and some basic software to get into the system. But I then needed to buy for him some further software (about £40) which he used to change the limits. Luckily Falken's recommendation on both front and back were only a gnat's difference so I did not need him to do it again.

After the tyres were fitted I started it up and the warning light stayed on for about 200 yards before it went out and has stayed that way ever since (touch wood).

 

[PeteandCher]

I wonder if a Fiat dealer would do it when presented with the evidence, ie a chart from the tyre manufacturer and a weighbridge printout?

 

[PaulW2]

My Hymer does not have a visible plate showing recommended tyre pressures, as cars do. I used to have Continental CP tyres and carried in my motorhome a print out of Continental's advice as to tyre pressures for axle weights.

Now I have changed to Falkens C tyres I carry a print out from Falken's website for tyre pressures for axle weights of C class tyres. At the top of that sheet it clearly shows that the information is for motorhomes as well as a range of commercial vehicles. I cannot see how anybody could possibly argue that my tyres or their pressures are not suitable, given that I am using the information from the best source, i.e. the maker of the tyres.

That gives rise to a few interesting questions.

In the event of an incident does it ever happen that someone goes around checking tyre pressures?
Also, are tyre pressures ever checked randomly, ie not necessarily after an incident?

My PVC, which as a "proper" vehicle still has its original tyre pressure sticker inside the driver's door, says it needs to be 5.5 bar - 79.5 psi - in its "freddi" state. This is irrespective of the tyres one fits, obviously.

It's only a 3.5t van, as built and as presently configured, yet to be ready when freddi it needs nearly 80 psi.

If there is a rule - if someone, the pneu police - were to investigate they would have me bang to rights if I run at lower pressures. Or I would need to argue the finer points of who the proper tyre pressure authority is - Fiat or Michelin - with a foreign policeman at the roadside. Good luck to me.

So I'm happy to defer to the expertise of the tyre manufacturers and run at lower pressures. However, I wouldn't want to get into any legal wrangle with anyone on this question in a country where the cops wear guns.

Could this happen? Has it ever happened to anyone? Or is it just my peace of mind, comfort and safety that matters?

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[peterc10]

That gives rise to a few interesting questions.

In the event of an incident does it ever happen that someone goes around checking tyre pressures?
Also, are tyre pressures ever checked randomly, ie not necessarily after an incident?

My PVC, which as a "proper" vehicle still has its original tyre pressure sticker inside the driver's door, says it needs to be 5.5 bar - 79.5 psi - in its "freddi" state. This is irrespective of the tyres one fits, obviously.

It's only a 3.5t van, as built and as presently configured, yet to be ready when freddi it needs nearly 80 psi.

If there is a rule - if someone, the pneu police - were to investigate they would have me bang to rights if I run at lower pressures. Or I would need to argue the finer points of who the proper tyre pressure authority is - Fiat or Michelin - with a foreign policeman at the roadside. Good luck to me.

So I'm happy to defer to the expertise of the tyre manufacturers and run at lower pressures. However, I wouldn't want to get into any legal wrangle with anyone on this question in a country where the cops wear guns.

Could this happen? Has it ever happened to anyone? Or is it just my peace of mind, comfort and safety that matters?

Yes, it is different with a PVC when compared with a C class or A class.

The problem with my A class is defining who is the relevant "manufacturer". Is it Fiat who only provided the engine, gearbox and front chassis and running gear? Or is it Alko who provided the rear chassis and running gear? Or is it Hymer who provided the rest, including the wheels, but not the tyres? Or is it the tyre manufacturer?

In my opinion it is the tyre manufacturer who is in the best position to recommend the pressures, once they know the axle weight you are running on.

 

[PeteandCher]

So Fiat made my van and put a sticker on the door shut stating 5.5 bar, they knew it was going to Malibu but had no idea what the build spec and therefore weights would be. I bet they put the same tyres and pressure stickers on even the little 5.4m vans. It's all a bit bonkers really.

 

[PaulW2]

So Fiat made my van and put a sticker on the door shut stating 5.5 bar, they knew it was going to Malibu but had no idea what the build spec and therefore weights would be. I bet they put the same tyres and pressure stickers on even the little 5.4m vans. It's all a bit bonkers really.

Yes, I think they just declare that the proper tyre pressure for these vehicles with these axle weights is X. Whether it becomes a campervan (which runs close to the axle limits) or a commercial van (which may also be up to the limits).

We depart from this for our own comfort. But at what risk? Probably not an increased risk on the road if within tyre manufacturers' specs, but I'm not sure I fully understand yet whether there is any authority which would, under any circumstances, look into it. Police? Insurers? Warranty claims?

 

[PeteandCher]

I cannot see the justification for saying that if it is a van it can be xxxbar, but if a camper it must be much higher. I don't see any difference between some furniture and my belongings, or a pallet of concrete blocks if the van weighs the same.

 

[PaulW2]

I cannot see the justification for saying that if it is a van it can be xxxbar, but if a camper it must be much higher. I don't see any difference between some furniture and my belongings, or a pallet of concrete blocks if the van weighs the same.

I think it's the opposite, isn't it?

"Under all circumstances, the recommended pressures for this Ducato van are 5.5 bar."

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[jerryz]

The Nexxans Van tyres i fitted 3 moths ago have improved the ride and handling by a massive degree over old Michelin Agilis crap