Tyre Pressures

[Philip]

Hi all

I have just purchased a Swift Kon-tiki 650T (1993)

The problem is finding the correct pressures.

The van was delivered with 35psi

The Swift handbook gives no pressures.

The Peugeot book gives 61psi

Can anyone put me on the right track

[Brian Kirby]

I think your current pressures are too low.  However, before you make any changes, first check that the tyres fitted to your van are those referred in the Peugeot handbook - probably Michelin XC Camping of a specified size.  If they are, and as a quick fail-safe, use the Peugeot handbook recommendation.    If they are not the recommended tyres, you'll need to take further advice before using your van.  Note make, type, size, load and speed ratings, and come back to us for your next step.

Second point, your van is now around 14 years old, so check their ages, especially the spare.  If they are the original tyres (unlikely - but possible), they are well beyond their use by date and all, including the spare, must be replaced forthwith.  Even if they are a second set, they may still be in need of replacement on grounds of age, irresective of the remaining amount of tread.

To find out more on this subject, use the search option above, enter the keywords "tyre pressure" (without the inverted commas) select "motorhome matters" from the forums list, set time to "one year", and then read, and be amazed!  You won't get a specific answer, but you will get answers to enable you to obtain definitive pressures.  However, as above, check what tyres, and their ages, are actually on your van before proceeding any further. 

[Philip]

Brian.

Thanks for your promt reply.

I have taken your advice and will be having a new set fitted on Tuesday (ouch).

They are bieng fitted by a commercial tyre fitter so I will have a good chat with them they should steer me in the right direction.

 

 

 

.

[Brian Kirby]

Philip

Make sure you know what he intends fitting.  If not Michelin XC Camping, which have certain load carrying advantages, I'd suggest you try to get another "Camping" branded tyre.  I note Continental are now doing a Vanco "Camping" tyre: their tyres have been well reviewed for motorhomes in Germany, and I believe Goodyear may also do one. 

The Michelins are constructed to a higher loadbearing capacity than is stated on the sidewall - to protect us silly motorhomers from the effects of our occasional overloads!  I don't know about the other makes in this respect.  Where the Michelins don't seem so good is in respect of grip on greasy roads and slippery campsites.  The Continentals look as though they may be a bit better in that respect.  I think the Germans reckoned their (but I don't think the test was specifically the "Camping" variant, that was tested, just standard Continental Vanco) wet road performance superior, but I have no experience of them. 

Make sure you know what are the maximum permissible front, and rear, axle loadings for your van.  This information may not be available to the tyre fitters after 14 years, but it will govern the tyre rating that is suitable.  Motorhomes frequently have reinforced rear suspensions, and hence a higher permitted rear axle load than a standard Boxer.

Good luck.

[enodreven]

Hi,

 

I would strongly suggest you arrange to have the van weighed on a weight-bridge and identify the actual axle weights as you would hope to use the vehicle e.g. with all the normal things you would hope to take with you, Once you have these weights then contact the tyre manufacturer and if that is Michelin then you can use this link to there web site

 

http://www.michelin.co.uk/uk/front/affich.jsp?codeRubrique=26&lang=EN

 

If you use the "Contact Us" link at the top of the page and give them the actual tyre details plus the axle weights they will email you back with their recommendations on the pressures you should use. Its worth printing off a copy of the reply and keeping it with your motor-home documents as if the pressures are found to be different from the motor-home/van cab manufacturers data then they could be used as a contributing fact in any accident so the email from the tyre manufacturer is a very important piece of paper

 

Sorry if a bit long winded but its really worth getting the pressures in writing ?

 

 

[Derek Uzzell]

I believe the only tyres available in the UK and specifically aimed at motorhomes come from Michelin, Continental and Pirelli ("CityNet Camper"). The range of available sizes is relatively limited and there is a tendency for sizes appropriate to older vehicles to go out of production. When I've asked for tyre-related advice in the past Michelin have always been helpful and so have Continental. (I've never needed to contact Pirelli.)

 

A couple of things worth bringing up that I don't think have been mentioned previously on the forum:

 

1. Tyre pressures should be measured 'cold'. However, this doesn't mean that weather conditions must be Arctic, just that pressure readings should be taken before the vehicle has been driven and the tyres warmed up. When I asked Continental to define "cold" I was told that "the benchmark in Europe is 20 degrees Centigrade, however please take this with a 'pinch of salt' and use whatever the ambient temperature is at the time of measurement".

 

It's critical that tyres are never overloaded or under-inflated. Michelin warn that, besides potentially damaging a tyre's structure, overloading by 20% reduces a tyre's life by 26%. Under-inflation has a similar effect - a 20% too low pressure will result in a 26% reduction in tyre life-span. It's far better to have a hard-riding motorhome with tyre pressures that might safely be reduced to improve comfort, than a soft-riding vehicle with tyre pressures that are too low to support safely the load being placed on the tyres.

 

2. When checking tyre pressures you need to be confident that the gauge being used is accurate. Tests have shown that service-station forecourt gauges can be untrustworthy and that hand-held gauges can become unreliable (particularly if roughly treated). I had always assumed that my own high-quality but ancient dial-gauge was providing correct information. In fact it was accurate at higher pressures (ie. for my motorhome's tyres) but was reading some 20% high at the lower end of the scale. This meant that the 29psi to which I was happily inflating my car's tyres was, in reality, a whole lot lower.

 

So, if you have your own tyre-gauge, it's worth trotting along to a friendly tyre-fitting firm now and again and asking them to check whether your gauge's readings match theirs. Once my gauge's inaccuracy had been identified I bought an expensive digital gauge that immediately failed, followed by a £5 dial-gauge that looks just like my old one, but reads to higher pressures. The latter is noticeably less well engineered but it is more accurate at lower readings. Having two gauges that I can 'calibrate' against each other means there's a fair chance they both won't suddenly go haywire simultaneously.

[Don Madge]

Philip - 2007-06-01 12:04 PM

 

Hi all

I have just purchased a Swift Kon-tiki 650T (1993)

The problem is finding the correct pressures.

The van was delivered with 35psi

The Swift handbook gives no pressures.

The Peugeot book gives 61psi

Can anyone put me on the right track

 

Philip,

 

I run my four year old Timberland with Goodyear Cargos at 56psi front and 62psi rear.

 

I've just replaced the original Cargos with the same so I still have a new spare. The tyres still had plenty of tread left after 46,000 miles

 

The brake pads are still going strong but they will be replaced in Nov on the MOT service before our long winter trip.

 

I spent the weekend at the Stratford show helping out on the Vicarious Books stall. I spoke to many motorhomers and very few knew the tyre pressures on their vans. One character went as far as to say he could not check the tyre pressures as the valves were pointing inwards. The mind boggles.

 

The weekend on the book stall was a real eye opener.

 

I met a few forum users who came up and introduced themselves.

 

Don

 

 

[Philip]

Thanks for all the imput peeps

 

I went to a commercial tyre fitter and after a long chat we arrived at 61psi front and 65psi rear.

 

Hope this helps anyone else with the same van

[enodreven]

Hi, Philip

 

Great glad you got it sorted, Albeit I would still get the van weighed and make contact with the tyre manufacture just to get something in writing?

 

 

Philip - 2007-06-06 8:23 AM

 

Thanks for all the imput peeps

 

I went to a commercial tyre fitter and after a long chat we arrived at 61psi front and 65psi rear.

 

Hope this helps anyone else with the same van