Continental Vanco

[djchapple]

My soon to be collected Devon Monaco based on the 2007 Renault master with the 2.5 litre engine has Continental Vanco 225 65R 16C 112/111R tyres.

 

I contacted Continental to determine the tyre pressure at various axle loadings and I have just received the following reply. :-D

 

_____________________________________

 

Thank you for your email.

 

Please find the information as requested.

 

44psi | 47psi | 51psi | 54psi | 58psi | 62psi | 65psi | 69psi

 

1550kg | 1655kg | 1755kg | 1855kg | 1950kg | 2050kg | 2145kg | 2240kg

 

Kindest Regards

 

Paul

 

Paul Ridler

Product Support Engineer

Continental Tyres Ltd

Technical Service Dept

88-98 Wingfoot Way

Birmingham

B24 9HY

 

_____________________________________

 

I'm sorry that I cannot get the tyre pressures and axle loads to line up properly. It looked Ok when I wrote it!

 

[Brian Kirby]

These are 10 ply rated tyres.

These pressures should only be applied to tyres by Continental, of the exact same size, type, and load/speed rating stated.

They should not be applied to any other manufacturer's tyres, even if of the same size, type, and ratings.

They should not be applied to Continental tyres of any other size, type, or rating.

Always:

A. Stick to the base vehicle manufacturer's / converter's recommended tyre pressures, or

B. Weigh the individual vehicle axles, with the vehicle fully laden, at a weighbridge, and then obtain written recommendations for tyre pressures from the tyre manufacturer - for those axle loadings. 

Do not depart from the pressures recommended at either A, or B, above without taking further expert advice.

[Derek Uzzell]

Brian:

 

A Continental 225/65 R16C 'van' tyre will be either a Vanco-8 pattern (most probable in this case, given that the Monaco is panel-van-based) or a VancoCamper pattern. In either case, this particular size of tyre is 8-ply rated.

 

(For the record, I believe the load index/speed rating is actually 112/110R.)

[Brian Kirby]

Apologies, my mistake.  I should have left the ply rating off!  However, my main point was to illustrate the hazards in quoting tyre-specific pressures that depart from base vhicle manufacturer's standard recommendations. 

I think we really shouldn't do it, as it just may be misapplied by someone in error.  My mistake, and the error over the load index/speed rating in the original post, seem to rather neatly make the point?

[djchapple]

I wish it was that simple Brian.

 

My Orian Pavo based on the 2005 Boxer had two plates on the door aperture. One on the front pillar said the tyre pressures were 80 psi all round and the other on the rear door pillar said 72 psi all around.

 

The tyres fitted were Kleber and they quoted tyre pressures for the axle loading for a lightly loaded van of just about 45 psi and for my fully loaded van of around 60 psi. The loading had some effect on the front axle loading but a much greater effect on the rear axle loading so why are the quoted tyre pressure independent of the axle loading.

 

Now what value do I select? In general the pressures quoted on motorhomes seem to be almost worthless and the converters never seem to be able to give you any helpful information.

 

The ridiculously high pressure of 80 psi seems to be recommended by only one tyre manufacturer and with this pressure the ride was pure torture. The values given to me by Kleber produced a ride that was far more comfortable and the van seemed to handle very well.

 

I am not an expert and do not pretend to be one I was just offering information given to me by Continental for the clearly identified tyres.

 

Forums in general are full of posts giving pressures used by the drivers based on nothing more than pure guesswork.

 

It seems that hard facts relating to tyre pressure are almost impossible to come by.

 

Finally one problem that seems to be always with us is how the Police would determine the "correct tyre pressures" if at any time we are challenged.

 

Their decision would be taken very seriously by the insurance company.

 

 

[Brian Kirby]

Hi David

I'm going to reply against your points, so am carving your post around a bit.  Hope you won't be offended!

My Orian Pavo based on the 2005 Boxer had two plates on the door aperture. One on the front pillar said the tyre pressures were 80 psi all round and the other on the rear door pillar said 72 psi all around. The tyres fitted were Kleber and they quoted tyre pressures for the axle loading for a lightly loaded van of just about 45 psi and for my fully loaded van of around 60 psi. The loading had some effect on the front axle loading but a much greater effect on the rear axle loading so why are the quoted tyre pressure independent of the axle loading. Now what value do I select?

There is no excuse for the converter, Orian, apparently failing to get the tyre pressures right.  Since the Pavo is a panel van conversion, with a 3,300 Kg MAM, I'm surprised that either pressure was on the plate.  However, it is the plate fitted by the converter that should govern the appropriate tyre pressures.  The tyre pressures set by the "chassis" manufacturer (Fiat) relate to the vehicle as it leaves their works.  The only logical reason for changing that would be if the converter (Orian) uprated the suspension, and then had to fit different wheels/tyres to take the higher loadings.  This may sometimes happen, but it does not seem to be the case with the Pavo. 

You haven't said which of Kleber's tyres were fitted, but the pressures you quote sound to me suspiciously close to those normally quoted for Michelin XC Campings.  The 72 psi being around the normal recommendation for the 15" wheels on the 15 Chassis, and the 80psi being around normal for the 16" wheel on the 18, or "Maxi", chassis.  Since the Michelin Campings are built to a higher load carrying capacity than their official 8 ply rating, the recommended pressures for them are higher than usual for tyres of their size/rating.  This is because Michelin recognized that motorhomes are prone to being overloaded, and are always relatively heavy, so made the "Camping" tyre more robust to cope.  If I'm right, and it is speculative, it would seem your chassis was delivered from Fiat with standard panel van tyres, which for its MAM would be fine, but got the wrong plates applied (twice) by Orian during conversion.  If so, the plated pressures would seem to have been dangerously high, so you did well to get Kleber's advice and drop them to what they recommended.

The reason the recommended pressures don't take account of actual axle loadings, is because axle loadings in use cannot be predicted by chassis manufacturers, or by converters.  This uncertainty over actual laden weights leads to the adoption of the "fail safe" strategy of setting the tyre pressures to either of a) the maximum pressure recommended by the tyre manufacturer, or b) a pressure required for the maximum permissible loading for the axle in question.  If a), the tyres will generally be able to carry more than the axle is permitted to carry, so an additional factor of safety is built in, if b) the tyres will carry at least what the axle is permitted to carry.  However, if you weigh each axle at a weighbridge, with the vehicle fully laden, and find that the actual loads fall below the permitted maxima, it is possible, with the advice of the tyre manufacturer, to adopt tyre pressures appropriate to the actual load, which usually results in better road manners in the vehicle and a more comfortable ride.

In general the pressures quoted on motorhomes seem to be almost worthless and the converters never seem to be able to give you any helpful information. The ridiculously high pressure of 80 psi seems to be recommended by only one tyre manufacturer and with this pressure the ride was pure torture. The values given to me by Kleber produced a ride that was far more comfortable and the van seemed to handle very well.

I don't think the converters are all quite as bad as you imply, my own experience with two vans has been that the converter correctly quoted the tyre pressures recommended by the chassis manufacturer (one Fiat, one Ford).  However, for reasons stated above, both set high pressures relative to actual loads.  I obtained the laden axle loads in both cases, relayed these to the tyre manufacturers (Michelin and Continental respectively) and made the adjustments to the running pressures, retaining a little in reserve for the usual variations in loading as we travel.  The results have been reassuring.

I am not an expert and do not pretend to be one I was just offering information given to me by Continental for the clearly identified tyres. Forums in general are full of posts giving pressures used by the drivers based on nothing more than pure guesswork.

Please don't misunderstand me.  I'm no expert.  I know only what I have been told by knowledgable others.  To be confident in the knowledge of those others, one must know their credentials: for that reason I only take advice on tyre pressures from vehicle, or tyre, manufacturers, making sure all such advice is in writing and identifiably from the company.  I am aware that many do post regarding tyre pressures, but I think they should not: because recommended pressures vary between tyre manufacturers even for apparently identical tyres, because few people trouble to read and fully understand the legend on their tyre sidewalls, and finally because advice on the pressure one owner adopts cannot possibly reflect the loadings under which another operates his motorhome.  Such advice is specific to the make of tyres fitted, their size, their load/speed ratings, the vehicle to which they are fitted, and to the conditions of load, speed, and temperature, under which it is operated.

It seems that hard facts relating to tyre pressure are almost impossible to come by.

Don't agree, but the advice must come from a credible source, as above.  The problem is that these vehicles are as easy to drive as, but much more complicated than, cars; and there is a lot more to know about loading, and using, them for best results.  In truth, they are little trucks, and not big cars.

Finally one problem that seems to be always with us is how the Police would determine the "correct tyre pressures" if at any time we are challenged. Their decision would be taken very seriously by the insurance company.

Not definitive, because I have no knowledge of what would actually happen in practice.  However, provided you have written advice from the tyre manufacturer on the correct tyre pressures for the actual loads on each axle, and provided the actual tyre pressures are no lower than those and the axle loads at the time no higher - and you can explain rationally why you have adopted those pressures - I cannot see why there should be a problem.  You'll be doing no more than any HGV driver should in adopting the correct tyre pressure for the load you are actually carrying.

[Derek Uzzell]

A follow-on to David's observation that "The ridiculously high pressure of 80 psi seems to be recommended by only one tyre manufacturer and with this pressure the ride was pure torture."

 

In fact, things are potentially worse nowadays since tyre manufacturers other than Michelin have begun to target the motorhome market. Continental's motorhome tyre range is called VancoCamper and, if you visit the related section of the company's website, you'll find a footnote saying:

 

"....size 215/75R16C....requires a front inflation with 5.25 bars and a recommended and permitted rear inflation with 6.0 bars."

 

That's roughly 76psi (front) and 87psi (rear), and you'll note nothing is said about these pressure-data being adjustable according to axle-load or vehicle design. Heaven help anyone running a relatively compact, lightly-loaded motorhome with 87psi in its 215/75 R16C VancoCamper rear tyres!

[djchapple]

hello Brian - many thanks for your lengthy and detailed reply. I very much appreciate the views expressed and I found nothing in it which could possibly have caused offence.

 

I can find only one point about which I must disagree and that is relating to the converters not upgrading the suspension. Auto-Sleepers base the Orian Pavo (and I imagine the Auto-Sleeper Symbol also) on the Peugeot Boxer MWB LX 290 van which has a MAM (or whatever the current name is) of 2900 kg. They then upgrade the van to a MAM of 3300 kg. This possibly means that the original Peugeot tyre pressure will be lower than the Auto-sleeper values. This is possibly the reason why tyre pressures of 80 psi and 72.5 psi are quoted.

 

Whatever the reason it should be made clear by the converter which of the two, if any, is the correct value.

 

 

[Stuart]

May I ask what e-mail address you used, tried twicw to contact them without success?

 

Stuart

[trooper]

I dont totaly agree you have to get pressures from the manufacturers in writing as 3 times I have had cause to ring them and twice it has been pointed out to me the pressures are on a chart they have( in fact last time thier chart didnt go low enough for my wieght/tyre size so i am over pressure slightly), so whoever rang them to check on your tyre pressures would get the same answer.

------------

[Brian Kirby]

I hadn't picked up on that Derek, but as the mods would be fairly extensive, I should have thought the suspension upgrades etc. would probably be carried out at the Sevel works rather than by Orian/Autosleepers.  At a guess they'd need new springs both ends plus uprated dampers, new tyres and possibly wheels.  Makes me wonder if yours had all that done on the production line, but then got the wrong wheels/tyres fitted. 

Whatever, you've got a new one now!  :-)  Happy travels.

[Derek Uzzell]

The SEVEL "Camping-Car Package" (CCP) comprised suspension upgrading and 'camping' tyres (invariably Michelin's XC Camping pattern). As Brian mentioned earlier, a front-and-rear tyres inflation-pressure of 5.0 bar (72.5psi) was specified in SEVEL workshop manuals for Ducato/Boxer vehicles fitted with 15" rims and having camping tyres. (5.5bar (80psi) all-round was advised in the SEVEL manuals for CCP-equipped chassis with 16" wheels.)

 

Derek's Pavo appears to have had suspension upgrades and somehow gained the Camping-Car Package tyre pressure recommendations despite not having camping tyres. I don't think it would have been a matter of the wrong wheels/tyres being fitted, as I believe a suspension upgrade with retention of the original wheels/tyres has been the norm for Auto-Sleepers' SEVEL-based panel-van conversions.

 

It might have been possible by studying the Pavo's data-plates to ascertain their point of origin, but, whatever the case, they were both incorrect. Kleber has never made camping tyres and an ordinary 'van' tyre of the size fitted to a Pavo would have a design maximum inflation-pressure no greater than 65psi. For non-CCP-equipped SEVEL Ducato/Boxer chassis with 15" wheels, the workshop manual specified 4.1bar/60psi (front) and 4.5bar/65psi (rear). These would have been appropriate for maximum permitted axle-loads.

 

It's perhaps worth adding that Auto-Sleepers has a certain notoriety (you can replace that with "dreadful reputation" if you so wish!) for providing iffy tyre pressure information and I recall been told a near identical tale to Derek's by another aggrieved A-S high-top motorhome owner. I also understand that the matter of inaccurate tyre-pressure advice was raised at the 2006 AGM of the A-S Owners' Club.

[Brian Kirby]

Interesting!  I wonder if that suspension upgrade is any more than a re-plating to raise the MAM to the total of the front and rear axle maxima?  To increase the actual axle loadings, they'd surely need to uprate springs and dampers, brakes, re-set the rear load sensors, and change the tyres (assuming you remember!).  No wonder I've always thought AS looked expensive!