# Guess the tyre pressures.



## deefordog (Dec 31, 2013)

For our Kontiki 669 Tag, I asked Michelin what pressures they'd recommend based on the following info:

225/75-16 CP tyres
Front axle @ 1400kg
Rear axle #1 (nearest to front wheels) @ 1300kg
Rear axle #2 (nearest to rear of MH) @ 1200kg

The above figures were obtained on a weighbridge and also with a Reich CWC and were within 1% of each other. Note that the total comes to 3900kg which is a lot less than Swift give for their base MIRO and we're laden except for 120kg of water.

Currently have all the tyres at 60psi but guess what Michelin said? Their answer surprised me somewhat.


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## KeithChesterfield (Mar 12, 2010)

Currently have all the tyres at 60psi but guess what Michelin said?

80psi?

Like it or lump it!


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## Techno100 (May 8, 2010)

40 psi rears


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## BrianJP (Sep 17, 2010)

5.5 bar all round ?


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## deefordog (Dec 31, 2013)

51psi front, 72psi on each rear axle.

The front figure I find low and the rear figure overly high. But I suppose when you look at the measured axle weights, the rears are approaching their max of 1500kg whereas the front (max 2100kg) has a long way to go.


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## cabby (May 14, 2005)

Have to admit that I considered 55 & 65 psi to be about right. would never had thought 75 on each rear axle.

cabby


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## deefordog (Dec 31, 2013)

Without going out and checking, I have a funny feeling that I recently put the fronts up to 65psi and they look a bit squashed at that. Dropping to 51psi on the fronts seems to go against common sense but heh ho. Being on an AL-KO chassis, the front end sits nose down as it is with the fronts at 65psi.

Typical, I ask the professionals (Michelin) for advice and now I'm doubting it. The MH runs OK with what pressures we have at the moment. Yes, the rear's a bit crashy over rough roads but I guess that's torsion suspension for you.


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## Techno100 (May 8, 2010)

Same tyres
Mine is 1920kg on the front with 65psi as advised by Michelin.

looks fine to me


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## peribro (Sep 6, 2009)

I believe that Michelin has recently changed it's policy on the recommended tyre pressures that it gives out for the rear axle . Because so many people overload their rear axles my understanding is that Michelin now routinely gives out the maximum (or close to) pressure for the tyres. Not so with the front axles where the recommended pressure in this instance looks right.

ps I've just checked the Burstner recommended pressures for the rear tyres (Michelins) on my tax axle van and they are 3.5 bar (51psi). That is for a maximum load of 1,500kg per axle. Below is the Burstner recommendations.


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## TheNomad (Aug 12, 2013)

There is no one size fits all.

I suggest three rule-of-thumb things to consider for ANY vehicle:.

1. Look at the tyre walls and see what the manufacturers MAX inflation setting is for each tyre that you have fitted. (Settings/checkings should always be with tyres cold). 
Don't go within 5psi of that max, and ideally not within 10psi.


2. Try the tyre at 10psi below max. 
Now LOOK at the tyre at that pressure.
Does it's sidewalls and tread area look balloony, or alternatively does it look unduly squashed at the bottom? 
Remember there should be some slight 'squashing' of the portion that is against the ground. If there is not, then you have it over-inflated.

2. Now DRIVE the vehicle. How does it behave? Is the drive really hard over bumps, or does the ride feel unduly 'soggy' with noticeable sway when altering your line. 
If too hard at front or rear (or both) then let out 5psi from the tyres on that axle and try again. Etc.


Once you've settled on the right pressures for your tyres on your vehicle, then keep the spare inflated to the highest pressure of the tyres on the road wheels.

Read the tyres, and use your judgment and experiment with the pressures to find what's right for your tyres fitted, your vehicle and your comfort level.


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## JockandRita (Jun 1, 2005)

Bridgestone 
Front = 3.9 to 4.1 bar. Rear x 2 axles = 3.5 to 3.75 bar.

Barum Vanis (by Continental)
Front = 3.25 to 3.75 bar. Rear x 2 axles = 3.0 bar.

These figures were based on maximum axle weights up to 2000kg (front) and 1500 x 2 (rear).

The Hymer manual gives pressures of 5.5 bar (front) and 4.5 bar (rear), which gave a horrendously harsh drive.

Neither of the above makes are camping tyres, but they are commercial van tyres. 

HTH,

Jock.


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## BillCreer (Jan 23, 2010)

80 rear, 55 front.


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## mentaliss (Oct 23, 2012)

Techno100 said:


> Same tyres
> Mine is 1920kg on the front with 65psi as advised by Michelin.
> 
> looks fine to me


 I guess you rubber cleaned the tyre and polished the wheel/cover and all for your photo shoot you all poser :lol: :lol: :lol:


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## drcotts (Feb 23, 2006)

This whole subject is really ridiculous as far as i am concerned and frustrating.
No i am not knocking anyones posts. Its just that the converters should providing this information. Its done for cars and this is based on the known designs and weight of the car and the possible uses that they will be put to..so what cannot motorhome converters provide this info. They have to get the design of the van approved for use on the roads, they know the designs and weights and max permissble loads.

Why the heck cant they contact the tyre manufacturers when they make the blooming thing and talk to them and come to an agreement for us and put this in the book. 

It wouldnt be beyond the wit of someone even to contact all the major tyre makers so see if theres any difference.

Am i being totally niave?

You can bet your boots if there was an accident someone somewhere would be saying "well thats not what we reccomend"

If i look on the door pillar of my van it says one thing but if i ring michellin they tell me another.

ridiculous

Phill


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## JockandRita (Jun 1, 2005)

drcotts said:


> If i look on the door pillar of my van it says one thing but if i ring michellin they tell me another.
> 
> ridiculous
> 
> Phill


Phill,

I couldn't agree more. You are absolutely spot on, with your way of thinking. :thumbright:

Cheers,

Jock.


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## mentaliss (Oct 23, 2012)

drcotts said:


> This whole subject is really ridiculous as far as i am concerned and frustrating.
> No i am not knocking anyones posts. Its just that the converters should providing this information. Its done for cars and this is based on the known designs and weight of the car and the possible uses that they will be put to..so what cannot motorhome converters provide this info. They have to get the design of the van approved for use on the roads, they know the designs and weights and max permissble loads.
> 
> Why the heck cant they contact the tyre manufacturers when they make the blooming thing and talk to them and come to an agreement for us and put this in the book.
> ...


 The problem here is that the tyre pressures sometimes shown on the cab door pillar's are from the cab/chassis provider ie; Ducato. Peugeot, Mercedes and so on, their pressures are based on the gross payload of the chassis and there in lies the problem because the chassis cab is sold on to the Motorhome manufacturers
who then proceed to mount a large furnished box mounted to the chassis from this point on the chassis cab is roughly 80-90% of the gross weight of the vehicle and your quite right at this point they are more than capable of ascertaining with the tyre Manufacture what the tyre pressures should be..also the dealership's have a responsibility here as well as they are selling the vehicle without
( in a lot of cases) knowing what the pressure's should be set at their current excuses are that they don't know what the purchaser will load their van to...dialogue between both parties might help


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## Spacerunner (Mar 18, 2006)

I thought that the tyre max pressure as embossed on the tyre only applied to North America.
Ask any dealer or garage or even Fiat themselves and the reply always seems to be whatever the base vehicle specification is.


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## TheNomad (Aug 12, 2013)

Spacerunner said:


> I thought that the tyre max pressure as embossed on the tyre only applied to North America.
> Ask any dealer or garage or even Fiat themselves and the reply always seems to be whatever the base vehicle specification is.


I think the air there is the same as we use in Europe.

:wink:


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## warty (Jan 21, 2006)

*Tyres*

For those who are interested 
I have just bought a .
Continental Vanco Camper tyre from Tyre Universe on the internet ,a 215/70/R15 109CP.
For £74.27 + vat 
Dated 07/14

Delivered in 2 days


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## mentaliss (Oct 23, 2012)

*Re: Tyres*



warty said:


> For those who are interested
> I have just bought a .
> Continental Vanco Camper tyre from Tyre Universe on the internet ,a 215/70/R15 109CP.
> For £74.27 + vat
> ...


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## 747 (Oct 2, 2009)

Dated 07/14 ?

Have I lost a year somewhere?

Do you not mean 07/13 ?


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## JockandRita (Jun 1, 2005)

747 said:


> Dated 07/14 ?
> 
> Have I lost a year somewhere?
> 
> Do you not mean 07/13 ?


No, as the first two digits represent the week, so that tyre would have been manufactured during the week beginning 16th Feb, 2014 (0714).

Cheers,

Jock.


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## alhod (Nov 1, 2010)

Fiat handbook for Ducato 2012 recommends specifically for Camper tyres 5.0atm front and 5.5 atm rear. That is 73psi and 80psi resp. Since I am loading up to max (1850 kg front, 2000kg rear) running over to France I put front at 70 and rear at 75 yesterday, drove 5 miles back from garage and it was like bouncing a golf ball! Previous was 66 front and 60 rear so might try going back towards those!
Alan


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## jobla (Jun 18, 2006)

*Tyre Pressures*

Hi
A very informative leaflet is available from Tyresafe.org. It contains a lot of useful info and will help you determine correct pressures based on wheel configuration and axle loading. Just type motorhome into the search box and you will find it.

Regards to all
Jobla

PS
Follow this link
http://www.tyresafe.org/tyre-safety/tyre-safety-information/240-tyre-safety-information-motor-homes


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## 747 (Oct 2, 2009)

JockandRita said:


> 747 said:
> 
> 
> > Dated 07/14 ?
> ...


Thanks Jock.

The perils of old age at work again. :lol:


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## Rapide561 (Oct 1, 2005)

*Tyres*

Hi

I run at 80 psi all round. Good fuel economy too.

Russell


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## drcotts (Feb 23, 2006)

When fiat made the chassis cab and printed the handbooj they didnt know what the chassis cab would be used for
Thats my point the pressures shoukd be calculated when the van is made and given by the coverter


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## JockandRita (Jun 1, 2005)

*Re: Tyres*



Rapide561 said:


> Hi
> 
> I run at 80 psi all round. Good fuel economy too.
> 
> Russell


Don't you find the ride to be a really hard one Russell?

Cheers,

Jock.


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## bigtree (Feb 3, 2007)

I asked Mercedes to check my tyre pressures when it was in for a service yesterday,guess what,they didn't do it.So today I did and they were well down,started pumping them up,got to the last one and it didn't have a valve cap on.I was setting them all to 55 psi but when I removed the pump from the last one it just blew all the air out of the valve,removed the wheel to find that the valve had corroded. :x When I phoned them they said they should have been checked,seriously pi**ed off.


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## deefordog (Dec 31, 2013)

*Re: Tyres*



JockandRita said:


> Rapide561 said:
> 
> 
> > Hi
> ...


But Russell carries umpteen bottles of booze and a million pairs of socks lol.

Russell - have you fitted that wooden bed yet in MC? :lol:


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## Rapide561 (Oct 1, 2005)

*Re: Tyres*



JockandRita said:


> Rapide561 said:
> 
> 
> > Hi
> ...


Not really no, it seems fine to me.

I will add though when I had a puncture repaired, the dealer in Wakefield asked me to sign the invoice stating I had asked for 80 psi as he had set the tyre at 56.

Russell


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## TheNomad (Aug 12, 2013)

*Re: Tyres*



Rapide561 said:


> Hi
> 
> I run at 80 psi all round. Good fuel economy too.
> 
> Russell


80 psi?

What is the manufacturers maximum psi (it's stamped on the sidewall) for those tyres?


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