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

 

[Dean14]

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.

Some great replies to my initial question - thanks.
Thanks to the weight of opinion expressed here and my own research I am erring towards replacing the Agilis Campers with Falken Allseason Van 11 121 rated. If ever required to explain why I am running lower pressures than the manufacturer of my motorhome recommended then I can refer to Falken's own recommendations for the axle weights I run and the fact that I am well within the load limit for the tyres. The pressure chart I received was forwarded to me by Falken. What I do not feel happy doing is simply reducing the pressure of the Agilis Campers (to any appreciable degree) as that action is not supported by either the tyre manufacturer (Michelin are as much use as a chocolate ashtray) or the motorhome manufacturer. I appreciate others are happy to do so and that's their personal choice.
I am also then faced with the TPMS constantly showing that the tyres are 'under inflated'. I drive with the tyre pressure display shown in the display anyway so I would like to think that I might notice one of the tyres dropping pressure should it ever happen. In reality I'll probably buy a TyrePal system and cover it that way. I appreciate that it is possible to have the system adapted via the OBD but am concerned that doing so might leave me at risk of invalidating my Fiat warranty. I have not been able to find an official Fiat dealer / agent who is prepared to do this for me - hence my reservations in getting it done while the warranty is still valid.
The whole situation is quite preposterous. Fiat have absolutely no idea what final weight the motorhome manufacturer will build a motorhome too and neither they or the MH manufacturer know what final weight it will be carrying or how that weight is distributed. Yet both parties assert that tyre pressures must be 5.5bar - absolutely ridiculous, and dangerous. Such pressures would actually overinflate many of the tyres mentioned on this thread (particularly for the axle weights of my MH and even lighter MHs) almost certainly reducing contact patch, adhesion and safety margins. I am amazed this situation exists.

 

[PeteandCher]

I totally agree with you. I am off to a Fiat Professional dealer on Thursday to find out why the built in TPMS system failed in the first week of ownership (brand new vehicle) and will have a chat about adjusting the set pressures to what I want it to be based on my tyre choice. Will report back after my visit.

 

[peterc10]

With regards to the TPMS, I have been told that it is mandated in all "modern" vehicles. I am not sure what "modern" means year wise, but if that is the case then if it fails or if you remove it, that would probably lead to an MOT fail.

My Hymer is a 2015 model that was built in late 2014 and I bought it from the dealer's forecourt in 2015. The TPMS was not mandatory because it was listed as a paid for option which was chosen by whoever was specced it. I am surprised that the fittings in the wheels have lasted nearly 10 years and 3 sets of tyres being fitted. When they do fail it will be a lot cheaper to replace with an external kit and remove the old kit if I could get it switched off via the OBD.

Would the fact that they no longer exist be an MOT failure given that they are not mandatory on my motorhome?

 

[Mleabon]

Some great replies to my initial question - thanks.
Thanks to the weight of opinion expressed here and my own research I am erring towards replacing the Agilis Campers with Falken Allseason Van 11 121 rated. If ever required to explain why I am running lower pressures than the manufacturer of my motorhome recommended then I can refer to Falken's own recommendations for the axle weights I run and the fact that I am well within the load limit for the tyres. The pressure chart I received was forwarded to me by Falken. What I do not feel happy doing is simply reducing the pressure of the Agilis Campers (to any appreciable degree) as that action is not supported by either the tyre manufacturer (Michelin are as much use as a chocolate ashtray) or the motorhome manufacturer. I appreciate others are happy to do so and that's their personal choice.
I am also then faced with the TPMS constantly showing that the tyres are 'under inflated'. I drive with the tyre pressure display shown in the display anyway so I would like to think that I might notice one of the tyres dropping pressure should it ever happen. In reality I'll probably buy a TyrePal system and cover it that way. I appreciate that it is possible to have the system adapted via the OBD but am concerned that doing so might leave me at risk of invalidating my Fiat warranty. I have not been able to find an official Fiat dealer / agent who is prepared to do this for me - hence my reservations in getting it done while the warranty is still valid.
The whole situation is quite preposterous. Fiat have absolutely no idea what final weight the motorhome manufacturer will build a motorhome too and neither they or the MH manufacturer know what final weight it will be carrying or how that weight is distributed. Yet both parties assert that tyre pressures must be 5.5bar - absolutely ridiculous, and dangerous. Such pressures would actually overinflate many of the tyres mentioned on this thread (particularly for the axle weights of my MH and even lighter MHs) almost certainly reducing contact patch, adhesion and safety margins. I am amazed this situation exists.

But even worse when I contacted Michelin to find out what my pressures should be based on my actual axle weights they wouldn't tell me. Presumably this was some sort of misguided liability reason.

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[PeteandCher]

Following on from my post on Monday, I drove to a Fiat dealer (not going to name them) with my Michelin Agilis CP tyres at 4 bar, which tallies with their chart for my weights. Have been at this pressure for a few weeks, handles well and not too rattly, with tyres never getting warm. They refused to look at the TPMS problem unless pressure was raised to 5.5 bar. Discovered a failed wheel sensor (now ordered), reset system and handed van back, all under warranty. Very nice people to deal with. TPMS showing 5.5 on 3 wheels, no info on other one. They must have done a good job as it lasted 3 miles before the "TPMS not available" light came on again! Then drove 40 miles home with everything shaking and rattling, massive understeer on dry tarmac because the tyres are over inflated even for a heavy motorhome, never mind a light PVC. It hurts me to change tyres on a new vehicle, but I'm going to have to get something sensible. Anyone want 4 Michelin CP tyres with only 2000 miles?

 

[PeteandCher]

Ps, further to above I may resort to Homer Simpson's way of fixing a warning light, ie put a bit of black tape over the light!

 

[dogster]

Hi
If it helps, I just fitted Hankook Vanco LTs and the garage set them at 60psi to replace the original 6yo Conti campers (yip 80psi on the rear). The difference has been unbelievable in terms of ride noise and soaking up road bumps etc. Can't vouch really for performance yet but it just seems nicer to drive all round. Felt fine in the wet last weekend too.
dogster.

 

[Apacheman]

Following on from my post on Monday, I drove to a Fiat dealer (not going to name them) with my Michelin Agilis CP tyres at 4 bar, which tallies with their chart for my weights. Have been at this pressure for a few weeks, handles well and not too rattly, with tyres never getting warm. They refused to look at the TPMS problem unless pressure was raised to 5.5 bar. Discovered a failed wheel sensor (now ordered), reset system and handed van back, all under warranty. Very nice people to deal with. TPMS showing 5.5 on 3 wheels, no info on other one. They must have done a good job as it lasted 3 miles before the "TPMS not available" light came on again! Then drove 40 miles home with everything shaking and rattling, massive understeer on dry tarmac because the tyres are over inflated even for a heavy motorhome, never mind a light PVC. It hurts me to change tyres on a new vehicle, but I'm going to have to get something sensible. Anyone want 4 Michelin CP tyres with only 2000 miles?

TPMS a fairly new thing on vehicles and we’ve all managed for donkeys years without them. Is it possible to get it switched off or mapped out?? Might even be cheaper than buying 4/5 tyres? I run the Agilis CP, front 60 rear 70 and the ride is fine.

 

[Dean14]

Some great replies to my initial question - thanks.
Thanks to the weight of opinion expressed here and my own research I am erring towards replacing the Agilis Campers with Falken Allseason Van 11 121 rated. If ever required to explain why I am running lower pressures than the manufacturer of my motorhome recommended then I can refer to Falken's own recommendations for the axle weights I run and the fact that I am well within the load limit for the tyres. The pressure chart I received was forwarded to me by Falken. What I do not feel happy doing is simply reducing the pressure of the Agilis Campers (to any appreciable degree) as that action is not supported by either the tyre manufacturer (Michelin are as much use as a chocolate ashtray) or the motorhome manufacturer. I appreciate others are happy to do so and that's their personal choice.
I am also then faced with the TPMS constantly showing that the tyres are 'under inflated'. I drive with the tyre pressure display shown in the display anyway so I would like to think that I might notice one of the tyres dropping pressure should it ever happen. In reality I'll probably buy a TyrePal system and cover it that way. I appreciate that it is possible to have the system adapted via the OBD but am concerned that doing so might leave me at risk of invalidating my Fiat warranty. I have not been able to find an official Fiat dealer / agent who is prepared to do this for me - hence my reservations in getting it done while the warranty is still valid.
The whole situation is quite preposterous. Fiat have absolutely no idea what final weight the motorhome manufacturer will build a motorhome too and neither they or the MH manufacturer know what final weight it will be carrying or how that weight is distributed. Yet both parties assert that tyre pressures must be 5.5bar - absolutely ridiculous, and dangerous. Such pressures would actually overinflate many of the tyres mentioned on this thread (particularly for the axle weights of my MH and even lighter MHs) almost certainly reducing contact patch, adhesion and safety margins. I am amazed this situation exists.

Well folks - the verdict is in. Running the Falkens at the manufacturers' RECOMMENDED pressures for my axle weights brings a huge improvement to the ride. We all know that running at 5.5bar is absolutely bloody ridiculous but equally ridiculous is Michelin's inflexible (get it ) attitude to the matter. I would urge anyone still suffering a crashy bashy harsh ride to swop to a tyre manufacturer that actually bothers to specify an inflation pressure for various axle weights; that's got to be the safer and much more comfortable option.

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[bigtwin]

Well folks - the verdict is in. Running the Falkens at the manufacturers' RECOMMENDED pressures for my axle weights brings a huge improvement to the ride.

And those pressures were …………

Ian

 

[BouncyBoatFolk]

TPMS a fairly new thing on vehicles and we’ve all managed for donkeys years without them. Is it possible to get it switched off or mapped out?? Might even be cheaper than buying 4/5 tyres? I run the Agilis CP, front 60 rear 70 and the ride is fine.

Ditto. When running at 70 psi /60 --Rear/Front readings from my standalone TPMS would show quite quickly the temperatures had risen pushing the pressures to 80/ 70. and above.
To keep to the prescribed pressures you'd need to be stopping every 10 mins to inflate or deflate a little.
Mike

 

[PeteandCher]

Well folks - the verdict is in. Running the Falkens at the manufacturers' RECOMMENDED pressures for my axle weights brings a huge improvement to the ride. We all know that running at 5.5bar is absolutely bloody ridiculous but equally ridiculous is Michelin's inflexible (get it ) attitude to the matter. I would urge anyone still suffering a crashy bashy harsh ride to swop to a tyre manufacturer that actually bothers to specify an inflation pressure for various axle weights; that's got to be the safer and much more comfortable option.

Well, actually Michelin do publish a chart of pressure v weight for their tyres, including the Agilis CP, but then in a footnote say that if it is a campervan ignore the chart and go for 5.5 bar even through that is above the maximum advised pressure on the chart. For the life of me I can't see what the contents of the van have got to do with it.

 

[peterc10]

And those pressures were …………

Ian

That will depend on the size of the tyre, it's maximum load rating and the actual axle weights you are running on.

 

[bigtwin]

That will depend on the size of the tyre, it's maximum load rating and the actual axle weights you are running on.

Agreed, but Dean14 is in possession of that information.

Ian

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[Dean14]

Bigtwin - mine is Fr 48psi & Re 55psi. Soooo much better. I've attached Falken's chart.

 

[JollyMazza]

Well folks - the verdict is in. Running the Falkens at the manufacturers' RECOMMENDED pressures for my axle weights brings a huge improvement to the ride. We all know that running at 5.5bar is absolutely bloody ridiculous but equally ridiculous is Michelin's inflexible (get it ) attitude to the matter. I would urge anyone still suffering a crashy bashy harsh ride to swop to a tyre manufacturer that actually bothers to specify an inflation pressure for various axle weights; that's got to be the safer and much more comfortable option.

Thanks for this info-overload everyone! Finally decided: Falkens going on the front next week, need to find a weigh-bridge?
Could work out pressures using Burstner formulas AxG : R= weight on rear axle, weight on rear axle - G = weight on front axle
A = distance between storage compt. & front axle in cm
G = weight of load in storage compt. in kg
R = wheelbase of the vehicle in cm
(I think : = divided) work all load compartments out & add together...
Tempting as the maths conundrum is, I think I'll get it weighed!

 

[Jofang]

Our new to us 2016 Hymer was fitted with a set of new tyres Conti CP, which were inflated to 80psi when we bought it. The ride was horrendous, so I reduced pressures to 70psi, which gave a marginal improvenent. After several posts on here a very kind chap from Conti technical sent me a weight/pressure chart. My pressures ard now down to 53psi and the ride improvement is enormous.

 

[AllesP]

Well folks - the verdict is in. Running the Falkens at the manufacturers' RECOMMENDED pressures for my axle weights brings a huge improvement to the ride. We all know that running at 5.5bar is absolutely bloody ridiculous but equally ridiculous is Michelin's inflexible (get it ) attitude to the matter. I would urge anyone still suffering a crashy bashy harsh ride to swop to a tyre manufacturer that actually bothers to specify an inflation pressure for various axle weights; that's got to be the safer and much more comfortable option.

Hi Dean,
I have just replaced 4 Michelin Agilis CP tyres, which came with the van at new, with recommended tyre pressures of 5.5 bar all round. The new tyres are Falken VAN01 225/75R 16 - 121/120.
Our Auto-Trail Tracker EKS's max load is 1850kg and 2000kg rear.
Can you tell me what tyre pressures Falken recommended please? The garage that fitted the new tyres put 60psi/4.1bar all round and I'm wondering if I should increase the rear tyre pressures to, say, 65psi/4.5bar.
Any advice would be welcome.
Thank you.

 

[Dean14]

Hi Dean,
I have just replaced 4 Michelin Agilis CP tyres, which came with the van at new, with recommended tyre pressures of 5.5 bar all round. The new tyres are Falken VAN01 225/75R 16 - 121/120.
Our Auto-Trail Tracker EKS's max load is 1850kg and 2000kg rear.
Can you tell me what tyre pressures Falken recommended please? The garage that fitted the new tyres put 60psi/4.1bar all round and I'm wondering if I should increase the rear tyre pressures to, say, 65psi/4.5bar.
Any advice would be welcome.
Thank you.

Hi Alles
See my post above on the 8/11/24 - I attached Falken's pressure chart