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Tyre pressures


Mickydripin

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Hi all,

 

this week I had to take my van to Birmingham to set up the TV dome as with the signal changes had knocked my tv out on some channels

 

It was the first outing since my van was serviced so I checked the Tyre pressures I got a bit of a shock as they were all 72 psi and I thought that was a bit high so I contacted the tyre maker Continental.

I sent them all the information and the weight that I normaly load the axels at and they came back with the following.

 

Front axel 1580Kg 50 psi.

Rear axel 1830Kg 68 psi.

Total loaded weight 3410.

 

When I took my van for its service it was unladen with a GVW of 2950 and continentat said that the pressures were well over the limit.

 

I contacted my Fiat Garage and they said that they were working off guides from Fiat.

 

On my tyres Continental Vanco camper 215x70xR15 CP 109R it says max pressure 69.

 

Mike.

 

Who is right and who am I to believe.

 

Can over inflation damage my tyres whilst it is standing?.

 

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Mickydripin - 2013-05-23 11:49 AM

 

Hi all,

 

this week I had to take my van to Birmingham to set up the TV dome as with the signal changes had knocked my tv out on some channels

 

It was the first outing since my van was serviced so I checked the Tyre pressures I got a bit of a shock as they were all 72 psi and I thought that was a bit high so I contacted the tyre maker Continental.

I sent them all the information and the weight that I normaly load the axels at and they came back with the following.

 

Front axel 1580Kg 50 psi.

Rear axel 1830Kg 68 psi.

Total loaded weight 3410.

 

When I took my van for its service it was unladen with a GVW of 2950 and continentat said that the pressures were well over the limit.

 

I contacted my Fiat Garage and they said that they were working off guides from Fiat.

 

On my tyres Continental Vanco camper 215x70xR15 CP 109R it says max pressure 69.

 

Mike.

 

Who is right and who am I to believe.

 

Can over inflation damage my tyres whilst it is standing?.

Conti, the Fiat place was working to white van man pressures they will have none for m/h.

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Mike,

 

I would also go with Conti's figures and here's why...

 

If you download the Tyresafe MH Tyre safety guide from here Link and look at page 4 you'll find a table of laod versus pressure for most popular tyre sizes.

Against your tyre size the lowest quoted axle load is 2005 kg with a corresponding pressure of 58 psi so 50 psi for your front axle weight should be about right.

And then against a single rear a load of 1832 kg equates to 69 psi so again very near (ignoring the fact that this was for a driven axle of course).

 

I doubt over inflation while standing will have done any harm, but it may have if you had driven at high speeds in hot ambients.

 

Keith.

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Mike

 

See this 2010 forum thread:

 

http://www.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Tyre-Pressures-Autotrail-Apache/18835/

 

Continental's website advice is that VancoCamper can be inflated safely to 5bar (approx 72psi), so 72psi is not 'over inflation'.

 

Fiat's tyre-pressure recommendations for vehicles fitted with 'camping-car' tyres go back decades to when Michelin's "XC Camping" pattern was first marketed and, for the 215/70 R15C size, Fiat's usual advice has been to use 5bar (72psi) for front and rear tyres.

 

You should not blame your garage for following Fiat's recommendations. Contrary to rupert123's statement, in inflating your tyres to 72psi, your garage will have taken into account that your vehicle is a motorhome fitted with camping-car tyres. If your vehicle had been a 'white van' fitted with common-or-garden light-commercial-vehicle tyres, Fiat's tyre pressure recommendations would have been lower and, presumably, your garage would have inflated the tyres accordingly.

 

Continental's inflation-pressure recommendations are available on-line and - for your size of VancoCamper tyres - match the 50psi(front axle) and 68psi(rear axle) advice you've been given by Continental.

 

Inflating your tyres to 72psi all-round would have not harmed them: in fact, if your motorhome were to be static for a long period (eg. during several winter months) received wisdom is that it's a good idea to inflate the vehicle's tyres to their recommended maximum pressure to cope better with the continuous load being placed on them.

 

Driving your motorhome with all its tyres at 72psi would likely result in a harsh ride. You MIGHT find that using 50psi for the front tyres makes your motorhome feel 'soft' at the front when cornering, but you'll have to suck it and see. If you notice that cornering feels imprecise, go to 60psi.

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Inflating your tyres to 72psi all-round would have not harmed them: in fact, if your motorhome were to be static for a long period (eg. during several winter months) received wisdom is that it's a good idea to inflate the vehicle's tyres to their recommended maximum pressure to cope better with the continuous load being placed on them.

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

Thanks Derek for your advice I may do that at the end of the season also thanks Rupert and Keith for your advice it is nice to know that there are people on this site that are there to help.

 

Mike.

 

 

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  • 3 months later...

Don't know if this helps but:

The side of my conti vanco campers 215/70 R 15 CP does state 69 psi max pressure but also states that as they are re-inforced camper van tyres they can be inflated to 5.5 bars (79 psi) max pressure. In fact the recommended pressure on my Adria 572 SL - on the stickers fitted inside the door is for 5.5 bars at the rear and 5 bars at the front.

Cheers

 

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My Fifer L came set to Citroen's pressures. Rock Hard ride which rattled what is a near silent camper in transit.

Weigh bridge figures last week were 1620 Kg front and 1460 Kg rear and 3080 overall Kg on a 3500 plate chassis full load.

On the tyre companies advice I dropped from 4.75 Bar to 3.75 all round. 55PSI.

On the first trip away to france last week the ride was far less harsh and apart from a slight unsure feeling at first I soon got use to the far more enjoyable ride. The tyre stayed cool and the only down side is a very slight soft steering feel. But I do mean very slight which at no time feels unsafe.

Peter

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Lowering a motorhome's tyre pressures from 4.75bar (69psi) to 3.75bar (55psi) should be expected to produce a significantly softer ride combined with noticeably less precise steering. 55psi is not a particularly low pressure for a panel-van conversion (PVC), though, so there's no real concern that it might cause tyre overheating.

 

For what it's worth, when the German motorhome magazine "Promobil" recently carried out comparative tests on six 215/70 R15C/CP tyres, using two Ducato panel vans and a La Strada PVC as the test vehicles, the tyres were all inflated to 4.0bar (58psi) for the front and rear axles.

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Guest 1footinthegrave
Interesting thread this, I've always inflated mine ( cold ) to 60 front 65 rear on my pvc, now I'm wondering if that is too high, and the only thing I wonder about is the accuracy of any garage or my own gauge though, and just as a heads up I've just had fitted some Falken R51 tyres, cannot get over how much quieter the van is. ;-)
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If you want a very accurate tyre gauge have a look at the Draper TPG 100A with a flexible hose.

 

I bought one about a year ago and took it to three local tyre depots to ask them to check how accurate it was.

 

They, very helpfully, did check and it came out no more than 1 psi in variation to all their professional gauges.

 

I can't remember what it cost but I'm pretty sure it was under a tenner.

1141470433_TyreGauge1.thumb.jpg.038d251963f2f2b38481cccb28b6cbf8.jpg

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chick2 - 2013-09-01 11:22 AM

 

If you want a very accurate tyre gauge have a look at the Draper TPG 100A with a flexible hose.

 

I bought one about a year ago and took it to three local tyre depots to ask them to check how accurate it was.

 

They, very helpfully, did check and it came out no more than 1 psi in variation to all their professional gauges.

 

I can't remember what it cost but I'm pretty sure it was under a tenner.

 

Commonly marketed as a Draper 69924, currently offered via Amazon at £8.75 and reviews are generally favourable.

 

Tyre gauges (or new ones at least) should all be pretty accurate (say within 1%). For a motorhome, a gauge capable of reading well over 100psi will normally be needed, as received wisdom is that gauges are most accurate in the centre 'window' of their design pressure range. If the motorhome has wheel-trims that mask the tyre-valve, care should be taken to ensure that the gauge can easily be connected to the tyre-valve. All digital gauges require a battery of some sort, and batteries have a habit of failing at the wrong moment. I've got 3 gauges - 2 analogue and 1 digital - and the analogue ones are easiest to use. All 3 gauges provide much the same readings at around 60psi, which is good enough for a motorhome.

 

If I remember correctly, 20°C is considered 'cold' by tyre manufacturers when providing inflation-pressure recommendations. A motorhome's tyres inflated to 60psi in the UK on a 0°C winter's day, are likely to read well over 70psi if the vehicle were then driven to Morocco and the pressures re-read there. It's not something to agonise over - just make sure tyres are not under-inflated and, if you must err, err high.

 

 

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1footinthegrave - 2013-09-01 9:48 AMand just as a heads up I've just had fitted some Falken R51 tyres, cannot get over how much quieter the van is. ;-)

 

I fitted Falken/Linam R51s over a year ago and an also impressed: a transformation in terms of road noise, ride comfort and grip on mud/wet grass in comparison to the Vanco Campers they replaced.

 

9000 miles later they are down to 9mm tread depth so they seem to be pretty durable too..

 

 

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