# tyre pressures



## rocky58 (May 11, 2005)

When I bought my motorhome in 2007 Lowdhams told me my tyre pressure 60psi in all of them.
Had it serviced and they put 80psi in all of them.
Decided to ring Michelin today they told me 80 in the back 51 front.My tyres are 215/75/P 16c Michelin XC camping tyre and axles weights 1360 front 1910 back fully loaded.They said if the load goes up at the front ring again and we will give you a new value

What do you think seems a bit low front


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## TeamRienza (Sep 21, 2010)

Hi rocky58,

Click through to this topic currently live.

http://www.motorhomefacts.com/ftopic-166361.html

I posted a reply with links to the tyresafe website where there are fairly comprehensive info on the pressures you should try.

You do need to know your regular axle weights though.

Cheers,

Davy


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## VanFlair (Nov 21, 2009)

Front should be OK with that axle loading.


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## peribro (Sep 6, 2009)

51psi is more than enough for that axle loading and should give you a much better ride. You could probably drop them to 45psi but if the ride is OK at 51psi, then leave at that.


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## drcotts (Feb 23, 2006)

If your van is the one shown in your avatar then the front sounds fine.


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## rosalan (Aug 24, 2009)

Owing to the weight distribution and orientation of the rear axle, there is comparatively little weight on your front axle. So raising the front tyre pressure would give you a poorer contact with the road surface as treads tend to bulge under pressure, with resulting poorer adhesion under breaking and cornering but just possibly a quieter ride.
As you are using Michelin tyres and have supplied your weight distribution, I would have thought that you will now have the optimum pressures for your specific vehicle, which is more than most of us have.

Alan


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## EJB (Aug 25, 2007)

My weights are similar and Michelin recommended 50 Front and 55 Rear.
They now always say 80 for the rears....but I will stay at 55 when I replace the tyres with the same models shortly :wink: 

When they recommended my pressures they commented that the front could be lower but they had to allow for weight transfer to the front axle when braking.


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## 113016 (Jun 5, 2008)

EJB said:


> My weights are similar and Michelin recommended 50 Front and 55 Rear.
> They now always say 80 for the rears....but I will stay at 55 when I replace the tyres with the same models shortly :wink:
> 
> When they recommended my pressures they commented that the front could be lower but they had to allow for weight transfer to the front axle when braking.


Good point there EJB.

Although, I am not in the low pressure camp, for heat reasons.
Under heavy braking, in an emergency situation, the load transfer could be substantial, and this could be a likely time for a tyre failure


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## andrewball1000 (Oct 16, 2009)

This thread solved it for me http://www.motorhomefacts.com/ftopict-101081-.html

See Grizzlyj post no 1000076 for the formula


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## 113016 (Jun 5, 2008)

andrewball1000 said:


> This thread solved it for me http://www.motorhomefacts.com/ftopict-101081-.html
> 
> See Grizzlyj post no 1000076 for the formula


Thanks Andrew and Grizzlyj, I am running Continental Vanco tyres and I have just done the calculation and out of interest, I have also sent an email to Continental.
I await a reply.
I have just checked my tyres and the wear is considerably noticeably less than the wear on my previous Michelin Agilis Campers, which did wear a lot faster than previous Michelin X Campers. I think the Agilis has a softer compound.
Or my Continentals came with much more tread depth, which is probably the case, therefore probably, a combination of both!
We tend to run heavy, therefore my pressures are
60psi front and 70 psi rear.
By doing the calculation, it would be 49 front and 61 rear.
So we will see, but I am quite happy with the ride


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## 113016 (Jun 5, 2008)

Just received a reply from Continental, less than one hour 8) 
I gave slightly higher weights, just in case of overload, and this is the reply
Front at 1580kgs = 3 Bar or 43.5 psi
Rear at 2000kgs = 4 Bar or 58psi
It does seem low for a fully laden vehicle, but they are the experts 

One thing I have noticed is that on the rear axle, they drop the psi down by 12psi for 150kg = 1 per 12.5kg
On the front they drop 26.5psi for 360 kg = 1 psi per 13.58kg

These figures were based on the side wall markings of 70psi at 11510kg


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## andrewball1000 (Oct 16, 2009)

Grath said:


> Just received a reply from Continental, less than one hour 8)
> I gave slightly higher weights, just in case of overload, and this is the reply
> Front at 1580kgs = 3 Bar or 43.5 lbs
> Rear at 2000kgs = 4 Bar or 58psi
> It does seem low for a fully laden vehicle, but they are the experts


It is good that Continental are prepared to give a recommendation. I found that Michelin just covered themselves with 80 for the rear which is why I found the formula so helpful in the absence of anything else.


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## 113016 (Jun 5, 2008)

Andrew, I just edited my above post with more info


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## 113016 (Jun 5, 2008)

I just sent a question to Continental and the reply states that the sidewall markings are for the USA market and don't apply for the UK 
Strange, must be for different safety laws.
The new lower pressure that they have supplied to me are from their data base and load per axle. They have no other information.


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## framptoncottrell (Jan 6, 2006)

If you have Continental tyres, the following booklet has everything you need:

http://www.conti-online.com/www/dow..._info/download/technical_data_book_pdf_bg.pdf

I have Continental VancoFourSeason (mud & snow) tyres fitted to my Morello XL and the recommended pressures are:

For fully laden: Front axle 2100 kgs 56psi; Rear axle 2400kgs 66psi
Normal running (weight checked on weighbridge): Front axle 1700kgs 43psi; Rear axle 1840 kgs 48 psi.
With my extra holiday baggage I use front 45psi and rear 50psi.

I have a TyrePal set-up and so far the maximum temperature I've seen in the tyres is 19° Celsius, which seems fine.

Dr (musical, not medical) Roy


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## Penquin (Oct 15, 2007)

Thanks to one and all for a VERY useful thread, I have just used the Tyresafe table and it tells me 44 front and 55 rear if laden which is exactly what I was told originally.

So one supporter here for the Tyresafe advice.

Thanks,

Dave


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## 113016 (Jun 5, 2008)

Just done the calculation as per framptoncottrell's link and it works out the same as Continental gave me. They must be using the same information.
Thanks for the link

http://www.conti-online.com/www/dow..._info/download/technical_data_book_pdf_bg.pdf


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## Cherekee (May 1, 2005)

I also have Conti Four Seasons and run 50/55 psi. Excellent tyres.

Alan


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## 113016 (Jun 5, 2008)

This morning, I have received another email from Continental, stating that I could increase the pressures up a little.
They recommend a little at a time, depending on driving style.
They first recommended 3 bar (44psi) for front and 4 bar (58psi ) for rear
The new up to are 3.5 bar (51psi) for front and 4.5 bar (65psi) for rear. 
My vehicle is pretty well fully loaded and running at full gross weight, but not full axle weights.
I must say, the service from Continental has been excellent, and it will make them top of my list for renewals.
I also add that the tyre wear has also been considerably lower, than my previous Michelins


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