Camping Tyres

[spike]

Hi,

I have a question regarding Motorhome ‘Camping’ tyres. As with many Motorhome, ours is now 7 years old as are the tyres, but the vehicle has only done 13600 miles. I’ve been informed that they should be changed due to their age. The existing Michelin 215/70R 15CP are very expensive compared to other tyres, and I wondered if they are really required, or can an alternative quality tyre be used? I found that Continental make one, but they are not so much cheaper, just £10 less each. On speaking to our local tyre outlet they recommend a Maxxis tyre as an alternative. Though I am keen to save money, I’m not keen to compromise on safety, and with this in mind I would like to get some facts on the matter.

According to the Hymer Vehicle ID plate the max gross weight is 3200 KG, with 1650 KG for the front axle, and 1750 for the rear. So if I get a commercial tyre which has a rating of 190/Q would this be adequate?

 

Your help on this matter would be very much appreciated.

 

The base vehicle is the Ducato diesel 2ltr JDT, 2004.

 

[hallii]

"Maxxis Tires are made by Cheng Shin Rubber, one of the largest manufacturers of tyres in the world. They are based out of Taiwan." So says Wikkipedia.

 

My personal experience of tyres made in the Far East (not Maxxis to be fair) was not a good one.

The wet grip was non existant, I swapped them for Continentals as soon as I could afford it!

 

I now only buy tyres that are from a well known EU based manufacturer, they cost more but they actually do what a tyre is supposed to do.

 

So my advice is buy the best you can afford, you will feel a lot happier braking from 70 mph in a thunder storm!

 

H

[crinklystarfish]

Hi,

This crops up from time to time and there is much you can read if you do a search. Below is a copy of my own last post on the subject.

"It might be stating the obvious but you have a world of choice. There is no obligation to stick to what manufacturers craftily market as 'camping car' tyres. I think they simply realise that in branding them as such results in people happily paying through the nose for them.

As long as the tyres you fit have a suitable speed and load rating you can fit what you like.

I personally have only ever fitted winter / mud and snow rated tyres to my motorhomes for the past few years and have benefited hugely. Getting stuck on wet grass just doesn't happen and driving in snow is much, much safer. I also played around with the air pocket and considerably increased the diameter of my last set (fitted to an X250 chassis). Running them at 55-60psi significantly improved the formerly somewhat choppy ride; they also made my speedo read correctly (it was about 10% out with standard tyres).

Oh, and that set was about half the price of 'sucker' branded tyres".

I wouldn't ever fit 'camping' tyres again, though I am persuaded by the argument to avoiding budget tyres of unknown provenance.

[Brock]

Michelin say that with regular checks, their camping tyre can do ten years if they are not subjected to harsh treatment. They still recommend 7 years though.

 

I replaced mine this summer after 7 years because I intend keeping the van for another 3 so they would need to be changed in the time I keep the van. ATS Euromaster did say I could leave them for at least another year. Might as well have them done now I thought.

 

I have limited knowledge of tyre brands and suitability. I replaced with Michelin Agilas Camping Tyres. Maybe I'm a mug but I am a happy one because I've had every confidence in Michelin's products over the years on my 9 cars and 5 motorhomes. I once bought cheap Chinese tyres for my car. Tried to go around a corner in the wet and the car decided to go straight on - fortunately down an empty side road. Once that was experienced, I didn't want it ever to happen again.

 

I wouldn't knock anyone who, with an informed opinion, can buyi cheaper tyres that do the job just as well. I think its good they get benefit from their knowledge. To me, it's about what you are prepared to pay for peace of mind for you and any passengers you carry.

[graementl]

Spike, have Avanz van tyres fitted to my Bessecarr 560 and advantage is that they are cheaper than camping tyres and should be used at a much lower pressure(50/54), result is better ride quality, Graeme

[flicka]

Hi Spike & welcome to the forum.

Tyres (choice of) is a subject that comes up frequently on the forum. If you use the "search" facility & put in one year it will bring up many previous threads.

 

In manufacturer speak "Camping" designated tyres are designed to cope with Motorhomes running close (or dare I say above) to their maximum weight limits for the majority of the time.

 

The reason many Motorhome tyres are replaced well before they are worn out, is due to degredation by UV light & this often shows in the form of the sidewalls cracking/crazing.

 

With your MAM @ 3200kg, I suspect that you run a lesser risk than most if opting for non "Camping" branded tyres.

 

It may be to your advantage to check the Michelin & Continental website for the manufacturer's recommended tyres for your vehicle weights.

[Brambles]

Copied from the Michelin website.

 

 

"After five years or more in service, your tyres should be thoroughly inspected at least once per year. If the need arises, follow the recommendations of the vehicle manufacturer regarding replacing the original equipment tyres. As a precaution, if the tyres have not been replaced 10 years from their date of manufacture (see how to read a tyre sidewall), Michelin recommends replacing them with new tyres. Even if they appear to be in usable condition and have not worn down to the tread wear indicator"

[Derek Uzzell]

Spike

 

There's a piece ("Tyre Traumas") on page 220 of Octber 2011's MMM magazine that may be worth looking at.

 

These are links to some 2011 tyre-related forum threads:

 

http://www.outandaboutlive.co.uk/forums/forums/thread-view.asp?tid=23261&start=1

 

http://www.outandaboutlive.co.uk/forums/forums/thread-view.asp?tid=24758&posts=6

 

http://www.outandaboutlive.co.uk/forums/forums/thread-view.asp?tid=23811&posts=4

 

http://www.outandaboutlive.co.uk/forums/forums/thread-view.asp?tid=22793&posts=14

 

http://www.outandaboutlive.co.uk/forums/forums/thread-view.asp?tid=22262&start=1

 

but (as has already been said) questions about motorhome tyres are regularly asked (Here's one from late-2007)

 

http://www.outandaboutlive.co.uk/forums/forums/thread-view.asp?tid=9860&start=1

 

and it would be a challenging task to try to summarise everything useful that's been said on the subject in the past.

 

If you want to use the forum's Search facility, I suggest you set Keywords to "camping-car" and Date Limit to "All posts" (omitting the quotation marks). This will produce an abundance of stuff going back to 2005, much of which won't involve tyres, but you should be able to select relevant threads by their headings.

 

Your present Michelin XC Camping tyres have a Load Index of 109, indicating a design capability of being able to cope with a ('single-wheel') axle-loadiing of 2060kg (1030kg per tyre). The "Q" Speed Rating equates to 160km/h (99mph). When selecting new tyres, you should ensure that their Load Index and Speed Rating are no less than 109 and Q respectively.

 

Purpose-designed 'camping-car' tyres are currently Michelin's "Agilis Camping", Continental's "VancoCamper" or Pirelli's "Chrono Camper". None of these will be cheap and (at present) there seems to be a serious Europe-wide shortage.

 

In principle, if you replaced your present XC Camping tyres with common-or-garden 'white van' tyres and your FULLY-LADEN motorhome's axle-loadings are both well below 2060kg, then this should be fine.

 

It would appear from on-line adverts, that you should be able to source fairly easily Continental's Vanco-2, Avon's AV9 Avanza, Toyo's H08 and Kumho's 857 patterns from (respectively) £88 per tyre down to £67 per tyre. You can get cheaper (eg. Maxxis), but I suggest you stick with a brand that has a reasonable reputation. Personally, I'd opt for the Continental Vanco-2 tyre if you can obtain them for around the £90 mark - I've now got Vanco-2s on my Hobby and I've no complaints. Shop around and, if you are going to replace all 5 of your tyres, you should be able to get a good deal.

 

Some caveats...

 

1. If you've been using the over-70psi inflation-pressures often advised for Michelin XC Camping (and other 'camping-car' tyres), you'll need to run 'white-van' equivalent tyres at lower pressures.

 

2. Make sure that whoever fits your replacement tyres uses the correct tyre-valve. It's almost certainly the case that your current valves are metal clamp-in ones. Normal practice is to replace just the core of such valves, but, after 7 years, it might be sensible to replace the complete valve. Discuss this with the tyre-fitting company as it's quite likely they won't keep suitable clamp-in valves in stock. DON'T be persuaded that an ordinary car valve will be "perfectly OK" as a replacement for a clamp-in valve. Either have just the existing valve-cores replaced or (preferably) have new clamp-in valves fitted.

 

The article in October's MMM speculates that replacing original-equipment 'camping-car' tyres with 'white van' tyres might be regarded as a notifiable modification by motor-insurance companies. The argument seems to be that a 'camping-car' tyre is purpose-designed for motorhome use, whereas a 'white van' tyre is not. So, if an accident occurred where tyres played any part, a motor-insurance company might consider that a motorhome originally fitted with 'camping-car' tyres, but now fitted with 'white van' tyres, now had 'inferior' tyres to the originals and that the vehicle's owner/driver might be considered to have failed in his/her duty of care. MMM's consultant, Barry Norris, suggests that motorhome owners would be best to contact their insurance company before 'down-grading' (my use of words) from 'camping-car' tyres to 'white-van' ones.

 

I've no idea how motor-insurance companies might react to such inquiries, though I have wondered myself whether moving from "CP"-marked tyres (which most recently-manufactured 'camping-car' tyres are) to 'white van' tyres might possibly have insurance implications.

[Brian Kirby]

With all due respect to the said Mr Norris, he may wish to chew upon this little nugget, if he is reading the "forum". Our van came on plain, common or garden, Continental Vanco tyres (pre Vanco2). Other Hobby Vans of the same vintage, from my own observations, were supplied on Vanco Camping Tyres.

Not quite sure how his advice would run under these circumstances!

The maximum tyre loadings, for similar size, section, speed and load rated tyres, in both Camping and regular "C" (commercial) designated tyres are from memory, the same, as can be seen in the Tyresafe Motorhome tyres leaflet. All that varies is that the tyre pressures for the stated loading, if using Camping tyres, is higher.

I was told by Michelin some years back the their Camping tyre was in fact a 10pr tyre that was sold as an 8pr, to be operated at 10pr pressures, so giving a substantial margin of safety in terms of load carrying capacity because they knew few motorhomers check weighed their vans/axles and consequently many ran overloaded. This appears to fit with Continental's Vanco Camping tyre, where one size from the range, although sold as a Camping tyre does not say VancoCamper on the sidewall and is in fact a 10pr C designated tyre. When in Camping guise it has, from memory, a downgraded load carrying capacity despite running at the higher stipulated pressure for a 10pr tyre.

There is some (verbal) claim by Conti that their camper tyres have a "four season" tread compound (to enhance soft ground adhesion, he said) allied to a summer tread pattern, so I assume this must be the case, though the logic of this somewhat escapes me.

[Robinhood]

Brian Kirby - 2011-09-24 10:08 PM

 

 

I was told by Michelin some years back the their Camping tyre was in fact a 10pr tyre that was sold as an 8pr, to be operated at 10pr pressures, so giving a substantial margin of safety in terms of load carrying capacity because they knew few motorhomers check weighed their vans/axles and consequently many ran overloaded. This appears to fit with Continental's Vanco Camping tyre, where one size from the range, although sold as a Camping tyre does not say VancoCamper on the sidewall and is in fact a 10pr C designated tyre.

 

I've always interpreted the Continental stance on "camping" tyres differently, Brian.

 

They state (for Vanco Camper tyres):

 

As the CP standard acc. to ETRTO is only valid for 8 PR tires, the 10 PR size 215/75R16C marked only as a „C“ tire requires a front inflation with 5.25 bars and a recommended and permitted rear inflation with 6.0 bars. Despite its C marking this tire provides safety reserves like a CP tire.

 

....from which I would deduce that all tyres designated as "CP" (i.e. "camping" tyres) should be of 8 ply construction, albeit with a greater level of reinforcement and perhaps sidewall stiffness. This would be why Continental don't (can't) designate the one (10PR) tyre in the Vanco Camper range as a CP tyre, even though it is manufactured to similar standards as the rest of the CP rated "camping" range, which are 8PR.

 

FWIW, my Hobby came supplied with Vanco (non-camping) tyres, and every recent Ford platform cab base I've looked at recently is in a similar state (albeit from different manufacturers). As I'm comfortable with the characterstics of the tyres, don't travel overloaded, and can get replacements somewhat more easily than CP rated tyres, I'm happy with that.

 

(and, as I've already stated before, this is the first motorcaravan I've had where the door pillar sticker for tyre pressures looks absolutely spot-on).

[Derek Uzzell]

Brian Kirby - 2011-09-24 10:08 PM

 

With all due respect to the said Mr Norris, he may wish to chew upon this little nugget, if he is reading the "forum". Our van came on plain, common or garden, Continental Vanco tyres (pre Vanco2). Other Hobby Vans of the same vintage, from my own observations, were supplied on Vanco Camping Tyres.

Not quite sure how his advice would run under these circumstances!

The maximum tyre loadings, for similar size, section, speed and load rated tyres, in both Camping and regular "C" (commercial) designated tyres are from memory, the same, as can be seen in the Tyresafe Motorhome tyres leaflet. All that varies is that the tyre pressures for the stated loading, if using Camping tyres, is higher.

I was told by Michelin some years back the their Camping tyre was in fact a 10pr tyre that was sold as an 8pr, to be operated at 10pr pressures, so giving a substantial margin of safety in terms of load carrying capacity because they knew few motorhomers check weighed their vans/axles and consequently many ran overloaded. This appears to fit with Continental's Vanco Camping tyre, where one size from the range, although sold as a Camping tyre does not say VancoCamper on the sidewall and is in fact a 10pr C designated tyre. When in Camping guise it has, from memory, a downgraded load carrying capacity despite running at the higher stipulated pressure for a 10pr tyre.

There is some (verbal) claim by Conti that their camper tyres have a "four season" tread compound (to enhance soft ground adhesion, he said) allied to a summer tread pattern, so I assume this must be the case, though the logic of this somewhat escapes me.

 

My understanding is that all Continental VancoCamper tyres are sidewall-marked "VancoCamper", but the 215/75 R16C 116/114R size (because it's 10-ply rated not 8-PR) is marked "C" rather than "CP".

 

There are many things discussed on motorhome forums and in magazines that have potential insurance implications. I can recall questions about improving motorhome braking where it's been suggested that 'racing' brakes might be fitted, or disk-brakes installed to replace the original drums. One forum member uses larger rear tyres on his vehicle as part of a MAM-uprating package, another has revised his motorhome's original gas system to an older standard, another (apparently) uses 'winter' tyres all year round. Many motorcaravanners have DIY-fitted rear-suspension air-assistance. You've speculated in the past about the possible impact on a car's Type Approval of adapting it to be A-frame towed. Any of these things MIGHT be taken into account in the aftermath of an accident.

 

As I've said before, if a motorcaravanner has his/her vehicle's tyres (and tyre-valves) replaced on a like-for-like basis, and uses 'handbook' inflation-pressures, then there should be no potential insurance/legality problems. This might be a costly exercise and the motorhome might not be pleasant to drive, but it's the KISS approach.

 

Personally, I can't see an insurance company quibbling (or being concerned) about a change from original "CP"-marked tyres to non-"CP"-marked ones provided that the latter had a Load Index and Speed Rating no lower than the former, but some motor insurance companies initially reacted bizarrely when they were told about winter tyres being fitted

 

http://www.telegraph.co.uk/motoring/road-safety/8184361/Motor-insurers-slide-into-winter-tyre-row.html

 

so it's impossible to guess what would happen if a motorcaravanner asked about replacing 'camping-car' tyres with 'white van' ones. I suspect that the real challenge would be trying to explain to an insurance-broker's representative what 'camping-car' and 'white van' tyres were in the first place and to justify replacement of the former with the latter without giving the impression that this would reduce safety.

[dikyenfo]

Also if you go down the road as I have with commercial tyres from my days with Transits and Ivecos where the same rim sizes put 225 section tyres on instead of the 215 more commonly fitted to perhaps stand the harder pressures applied.

So long as you have the standard chassis you can fit the wider tyres and a quick check with full lock applied in both directions will tell you and for the rears check any add-on fairings around the tyre area as well.

The extra rubber on the road is definetly an advantage and will seldom need more than 60 psi for most MH's.

Ask the commercial boys for their advice they are not stupid you know and have nothing to gain by giving you duff gen.

[Derek Uzzell]

Robinhood - 2011-09-25 8:31 AM

 

As the CP standard acc. to ETRTO is only valid for 8 PR tires, the 10 PR size 215/75R16C marked only as a „C“ tire requires a front inflation with 5.25 bars and a recommended and permitted rear inflation with 6.0 bars. Despite its C marking this tire provides safety reserves like a CP tire.

 

I'm going to e-mail ETRTO to see if they will send me details of the standard (and any testing criteria relating to it) for "CP" tyres. Can't say I'm confident I'll get a reply, but you never know your luck! If that fails, then I'll have a go at Michelin and/or Continental.

 

Much of the argument about 'camping-car' tyres versus 'white van' tyres seems to based around whether or not the former is significantly different from the latter and, hence, potentially worth paying a premium price for. A Continental Vanco-2 tyre in 215/75 R16C size is available as 8PR or 10PR. A VancoCamper 215/75 R16C tyre is 10PR. While it's reasonable to assume that a 10PR VancoCamper might be 'better' than an 8PR Vanco-2 for a heavy-ish motorhome, would it automatically be 'better' than a 10PR Vanco-2 just because it's a 'camping-car' tyre?

 

If it were known what the ETRTO standard is for a 'camping-car' tyre, it might be practicable to make a value judgement.

[Derek Uzzell]

dikyenfo - 2011-09-25 8:51 AM

 

Also if you go down the road as I have with commercial tyres from my days with Transits and Ivecos where the same rim sizes put 225 section tyres on instead of the 215 more commonly fitted to perhaps stand the harder pressures applied.

So long as you have the standard chassis you can fit the wider tyres and a quick check with full lock applied in both directions will tell you and for the rears check any add-on fairings around the tyre area as well.

The extra rubber on the road is definetly an advantage and will seldom need more than 60 psi for most MH's.

Ask the commercial boys for their advice they are not stupid you know and have nothing to gain by giving you duff gen.

 

Modern motorhomes are Type Approved and their tyre/rim size and specification will have been detailed on the vehicle's Certificate of Conformity. Fitting different profile tyres, or different rims, will conflict with the vehicle's Type Approval status.

 

Casual clearance checks won't necessarily take into account suspension deflection under hard braking/cornering or suspension upward movement under severe load. I'd also argue that, unless you need to exploit the extra load-carrying capability of a tyre with a cross-section different to the originals, it's pointless making a minor change.

 

I don't believe that swapping a light commercial vehicle's original 215/70 R15C tyres to 225/70 R15C and adjusting the inflation-pressure downwards would make any worthwhile difference to that vehicle's on-road (or off-road) performance. All you'd be doing is risking potential tyre-clearance problems and (possibly) making it impracticable to fit snow-chains.

[spike]

Hi all,

 

I must say that I am very impressed with the response to my question, really helpful and informative stuff, I really appreciate it. As I originally assumed then, if the replacement tyre is of equivalent Load Index and Speed Rating it should not be a problem. All this started for me after taking the van to be re-tracked as one tyre was showing wear when they informed me that the tyres were 7 years old and needed changing at £140 each! I must admit to being peeved about this given that the tread on the 2 rear tyres are as new. I will now do as recommended and check the condition of the tyre walls and if they are ok I will have saved myself a bundle.

I don’t have much experience with motorhomes as I have only recently purchased it (about 3 months ago; Hymer 494) and it’s taken me a while to familiarise myself with it all. We previously had a small campervan, which I converted myself, a project that I found as a Joiner very interesting. This vehicle was great fun, but too little elbow room for my liking.

So thanks again for the info, and I look forward to sharing knowledge with you in the future.

Spike

 

[Brian Kirby]

Derek Uzzell - 2011-09-25 9:31 AM

 

................................. A Continental Vanco-2 tyre in 215/75 R16C size is available as 8PR or 10PR. A VancoCamper 215/75 R16C tyre is 10PR. While it's reasonable to assume that a 10PR VancoCamper might be 'better' than an 8PR Vanco-2 for a heavy-ish motorhome, would it automatically be 'better' than a 10PR Vanco-2 just because it's a 'camping-car' tyre?

 

It is this, plus my conversation with the Michelin technical chap, as referred to above, that makes me think the Camping tyres are, to all intents and purposes, 10pr tyres marketed as 8pr.

 

A 215/75 R16C 113 tyre can sustain an axle load of 2,300kg inflated to 4.75bar. The same size/rating Camping tyre requires 5.5bar for the same axle load. In both cases, 2,300kg is the maximum axle loading permissible. (BTMA TyreSafe "Motorhome Tyres")

 

The carcass of a tyre has to be strengthened for it to support a higher load, and a higher pressure is then necessary to sustain its correct profile under load.

 

My understanding is that ply ratings are only truly applicable to cross ply tyres, but are now applied to radials because the term had become familiar to the trade. In effect, radials may have the same, more, or more commonly, fewer, "plies" than the number suggested by their nominal ply rating.

 

It is the higher pressures for load for camping tyres that seems to me to give the clue that they are made to a higher "ply rating" (that is to say a stronger carcass) than their actual load index suggests. Logically, this would be essential, since the higher pressure in any case requires a stronger carcass. In effect, this provides an enhanced safety factor (because the permissible axle load remains to all intents and purposes the same as for the equivalent C tyre) in recognition of the tendency of many motorhomers, in innocence, to overload, especially at the rear.

 

So, it seems to me, that what one is actually getting is, as above, something that if not actually a 10pr tyre, is a tyre that equates to something very similar. That, and relatively smaller volume of production, presumably explains the increased cost. It would be very interesting to know what reply ETRTO eventually gives, though, as I really can't see the logic of the above over simply specifying a 10pr tyre where the vehicle is a motorhome and the normal fit would be 8pr. I wonder if they'll be prepared to clarify?

[Robinhood]

Brian Kirby - 2011-09-24 10:08 PM

 

The maximum tyre loadings, for similar size, section, speed and load rated tyres, in both Camping and regular "C" (commercial) designated tyres are from memory, the same, as can be seen in the Tyresafe Motorhome tyres leaflet. All that varies is that the tyre pressures for the stated loading, if using Camping tyres, is higher.

 

Further to my previous "picking up" of your interpretation, Brian, please forgive me for also taking this particular statement to task as well. ;-)

 

Edit - and sorry - this was posted in parallel with your further post directly prior to this and inadvertantly ignored the relevant issue of a driven rear axle . :-S

 

In fact, the leaflet that you reference seems to show broadly the same profile of pressures and loading for both types of tyre, but only when the "Camping" tyre is installed on the front axle or the rear axle is undriven. (at least for the corresponding profile samples I've looked at).

 

If the "Camping" tyre is installed on the rear axle, this is driven, and is a single rather twin wheel fitment, then significantly higher pressures are recommended for the same load.

 

For example, using the 215/75 R16C (113) for my own 'van:

 

- a standard tyre is rated up to (front or rear axle) 2300kg at 69psi

- a CP (Camping) tyre is rated for the front axle (or undriven rear axle) up to 2300kg at 69psi

- a CP (Camping) tyre is rated for the driven rear axle up to 2300kg at 80psi !!!

 

 

Now......I have had advice twice from Michelin on tyre pressures for Camping tyres, and in each case they have quoted pressures which relate almost exactly to those quoted in the Tyresafe leaflet for the ordinary commercial tyre, (and, by nature of the argument set out above, pressures quoted for the use of a CP rated tyre as above). The recommended pressures were not uplifted for the rears, in line with the tyresafe leaflet. I can confirm that, since the recommended rear pressure was some 15psi less, and the front some 19psi less, than those on the door pillar, I restated my query and clarified that these reduced pressures really were correct with "Camping" tyres for my maximum axle loads.

 

(FWIW, the front pressures recommended were higher than the tyresafe leaflet, but absolutely conformed to the practice that Michelin then had (as I understand it) of allowing an additional 10% over the stated front axle loading to allow for weight transference under heavy braking).

 

Such practice leaves quite a lot of questions unanswered about whether or not Camping tyres are a requirement. (and indeed why higher pressures are still recommended for undriven rear axles).My theory, which I know is shared by others, some of whom have taken part in this debate, is that this has much to do with the prevalence of 3500kg MAM 'vans which are (particularly on the continent where this break-point has been historically more restrictive than the UK) either knowingly or unknowingly regularly used at well beyond the maximum MAM and axle loadings. The thought is that the Camping tyres were introduced to cope with such overloading, and that in fact they are capable of handling higher loads than that implied by the load index (but at a higher pressure than similar non-camping tyres). Since it is nearly always the rear axle that is beyond its limit in an overloaded motorhome, it is not surprising that higher pressures are recommended for use on that axle only (and again, it is also not surprising that, if you specify a weighbridge measured actual rear axle loading, you will probably get a lower recommended pressure than the maximum).

 

(I restate that the above is only conjecture, and I understand that Michelin - though not necessarily other tyre manufacturers - have recently stopped recommending anything but the maximum pressures for camping tyres on the rear axle, though front axle pressures seem still to be quoted in line with the approach set out above. I could think of a number of reasons why this might be so, but it's probably best not to further develop the argument(s) on a public forum ;-) )

[Brian Kirby]

What you say is correct, Robin, but is not the point I was trying to make.

 

What I was driving at, as stated in more detail in my post above, is that the "Camping" tyre, that many seem to assume is merely a marketing ploy to justify higher cost, is in fact a stronger tyre than it appears to be from its load and speed indices. I was using the comparison between pressures for load to illustrate why I believe this to be the case.

 

Which axle the tyres are fitted to seems to me irrelevant for the comparison, a maximum is a maximum, the tyre knows not whether it is at front, rear, or one of a pair. My point is simply that, for example, a 215/75 R 16 C 113 tyre cannot be inflated to 5.5bar, wherever it is fitted, whereas a 215/75 R 16 CP 113 tyre can. That higher pressure seems to me to imply that the actual carcass of the tyre must be stronger, to be able to sustain the higher pressure, and so is actually more than an 8pr, which is in other respects what it is sold as. So, my conjecture is that such tyres are, more or less, 10pr equivalent tyres. Inflated as then recommended, wherever mounted, they can actually sustain axle loads higher than the load index would suggest, and this is the undeclared safety factor that is deemed to justify their extra cost.

[Robinhood]

Brian,

 

I think we are largely violently agreeing (lol) (and indeed seem to be using very similar words for much of our argument).

 

The core issue that I was commenting on was that, though I agree the maximum permissible pressures on a CP rated tyre are significantly higher than on a similar rated non-CP tyre, (and that leads to the the possible conclusion that we both have made - using your words.....

 

"Inflated as then recommended, wherever mounted, they can actually sustain axle loads higher than the load index would suggest, and this is the undeclared safety factor that is deemed to justify their extra cost".....my post said something very similar.)

 

....you seemed to me to be stating that Tyresafe leaflet recommended higher pressures across the load spectrum for CP rated tyres than for ordinary commercial tyres of a similar designation.

 

In fact, Whilst higher pressures are permissible I can't see that they are recommended unless the CP tyres are used on a driven rear axle (though the higher pressures recommended in this case go some way to support the conclusion above).

 

For any front axle, and a non-driven rear axle (as is the case on most common front-wheel drive motorhome base chassis) the recommended pressures for CP rated tyres align very well with those recommended for standard commercial tyres - which begs the question why the recommendation that comes with the vehicle invariably amounts to using 5.5 bar for CP rated tyres.

 

It gives a safety margin it is true, but at the cost of regular visits to the dentist for new fillings for those people who operate the 'van within the legal weight restrictions (at which, 5.5 bar all round is likely to give a very hard ride).

 

...and if the above is the case, then it seems somewhat peculiar to me to almost encourage people to overload their vehicles by providing a significant margin on the tyres, whilst potentially not doing so on other components - though I must admit I'd rather those that do it had the safety margin - they just might be driving down the same road as me 8-)

 

Just to illustrate,the previous Ducato Maxi had maximum axle weights of 1850/2120kg. The Door pillar recommendations on Camping tyres were generally 5.5 bar all round (80psi in round terms). The recommended pressures from the tyresafe leaflet for these maxima (at which combination it would be illegal anyway to run a 3850kg rated vehicle) would be around 54(extrapolated)/64psi. Michelin added 10% to the front load to allow for weight transference and recommended me 60/64psi.

 

I had my vehicle weighed, and was within the maxima, so decided to live with the pressures quoted. I can assure you that the handling and roadholding characteristics were much better at the reduced pressures than previously (for two 'vans on the Ducato Maxi base), and as such, I for one am unconvinced about recommending very high pressures "just in case" of overloading. Which particular risk is worse? (rhetorical question).

 

[crinklystarfish]

The 3.5 tonne horsebox community are on the back foot with weight limits and are enthusiastically targeted for prosecution. White van man can often be seen bouncing off the bump stops. A particular kind of twin-wheeled dropside flat back is regularly and obviously overloaded with scavenged metals. 

If manufacturers were indeed so charitable there’d be an argument that they would cater for these potentially overloading eventualities too, and build all their ‘commercial’ tyres with a higher spec than stated on thesidewalls. Why are we special? 

We’ll probably never get to the truth regarding whether the premium price asked for ‘camping’ tyres is justifiable, but it’s funny how there always seems to be a premium price ‘branding’ aimed at relatively affluent leisure markets. 

Conversely, I’m pretty sure manufacturers are confident they wouldn’t make a killing with a ‘pikey’ branding strategy aimed at the Dale Farm community – and get away with charging double the price of a standard commercial tyre based on some ‘secret’ built in safety margin. 

What I do know with great certainty is that camping tyres are very expensive, crap on wet grass, and I’ll not be buying any.

 

[euroserv]

Hello,

 

I would like to agree with just about everybody!

 

All i would add is that 10 ply tyres are available from many reputable manufacturers with or without M+S tread patterns at considerably lower cost than the 'pseudo 8 ply' CP tyres discussed above.

 

Admittedly we buy at wholesale prices but the difference between prices of a two ostensibly similar tyres at 215 75 16 (8pr 111/113) and 215 75 16 (10pr 114/116) is only about £5!

 

We use Hankook RA08 as first choice followed by Avon AV9 for our vans. We have looked at Michelin and Continental but there are insufficient benefits to justify the increased purchase cost.

 

I am completely sure that the CP tyre bandwagon is only an instrument for lightening your wallet, and that the disguising of 10pr tyres as 8pr is 'for your own good' because you tend to run your vehicles close to your MAM more of the time than typical vans do. If you agree with this and also accept that the 7 year guidelines apply equally to van tyres as they do CP tyres then what benefits are there really?

 

Buy a higher rated tyre destined for a heavier van from a proper maker and your insurance company should give you a bigger discount! Unless of course they realise that you only drive it for 14 days a year anyway!

 

Nick

[pepe63xnotuse]

euroserv - 2011-09-28 12:03 PM

 

Hello,

 

I would like to agree with just about everybody!

 

Nick

 

 

Pace yourself though Nick!..as give it another month or two and all the "talk"(bickering?)will be about Winter/M+S tyres! (lol) (lol)

[spike]

flicka - 2011-09-23 9:51 PM

 

Hi Spike & welcome to the forum.

Tyres (choice of) is a subject that comes up frequently on the forum. If you use the "search" facility & put in one year it will bring up many previous threads.

 

In manufacturer speak "Camping" designated tyres are designed to cope with Motorhomes running close (or dare I say above) to their maximum weight limits for the majority of the time.

 

The reason many Motorhome tyres are replaced well before they are worn out, is due to degredation by UV light & this often shows in the form of the sidewalls cracking/crazing.

 

With your MAM @ 3200kg, I suspect that you run a lesser risk than most if opting for non "Camping"

branded tyres.

 

It may be to your advantage to check the Michelin & Continental website for the manufacturer's recommended tyres for your vehicle weights.

 

Hi Flika,

 

Took your advice and contacted Michelin regarding this issue, and asked that if I was to replaced the tyres with a commercial tyre of the same load index of 190 and a speed index Q would I be conforming to the legal requirement? If not, could they tell me what the specific difference was to other tyres of the same specification?

 

In response they stated that it would be legal as long as I stuck to the load and speed index of the vehicle. They also stated that if the replacement tyre has on 'C' after the 15 this will only be capable of taking 65psi on the rear axle, where as the Michelin XC CAMPING 215/70 R 15CP 109Q is capable of taking 80psi, and that the recommend pressure for my Motor home with front axle weight of 1650 and a rear axle weight of 1750 - will be 55 PSI (front) and 80 PSI (rear).

 

It was also stated that if I was to change from ‘CP’ to 'C' that I should notify my insurance company.

 

[Brian Kirby]

Robinhood - 2011-09-27 11:00 PM

 

Brian,

 

I think we are largely violently agreeing (lol) (and indeed seem to be using very similar words for much of our argument).

 

Agreed! :-)

 

..............you seemed to me to be stating that Tyresafe leaflet recommended higher pressures across the load spectrum for CP rated tyres than for ordinary commercial tyres of a similar designation.

 

In fact, Whilst higher pressures are permissible I can't see that they are recommended unless the CP tyres are used on a driven rear axle (though the higher pressures recommended in this case go some way to support the conclusion above)...........................

 

My fault, it was written in haste on a free (but very slow!) campsite WiFi link. :-)

 

The recommendation I had in mind is that from the vehicle converter who, I think logically, either quotes the maximum sustainable (often CP) tyre pressure for the tyre size fitted to the van, or pressures related to the maximum permissible load for each axle. Since the standard issue van will have a MAM lower than the sum of the axle maxima, this inevitably results in excessive pressures for one, or other, or both, axles. The converter's problem, of course, is that he cannot know how a given customer will load his van, so giving pressures for the maximum permissible is the simple, safe, option.

 

It was certainly recognised by Michelin that owners of motorhomes were generally ill-informed regarding the loading of their vehicles, and I was given to understand that this had resulted in a number of tyre failures in France, with Michelin becoming anxious that the reputation of their tyres was being questioned by the motorhoming fraternity. So, as a defence, they introduced the "reinforced" Camping tyre, that could sustain the types of overloads they considered relevant. These were sold as (nominally) 8PR, because they were then rated as for the standard fit "C" type tyre, so specifically could not be claimed to be condoning overload. My informant was vary cagey on this last point. Michelin did, and presumably do, not wish to seem to be saying it is OK to overload, because this would place them in a "difficult" legal position. Besides which, the overload is not just relevant to the tyres, but also to the vehicle suspension, brakes etc, which are not Michelin's proper concern.

 

So, it seems the extra strength is there, but tyre manufacturers find it legally difficult to make a public admission as to why. This is undoubtedly why spike is being advised to use pressures relevant to his axle maxima. Were he to take his van to a weighbridge, get the individual axle weights, and then consult the TryeSafe booklet (or Michelin tech in writing), I think he would find he can safely use lower pressures.