# Tyre pressures (again) New advice.



## Chudders (Jul 5, 2008)

A couple of weeks ago I e mailed Michelin with my tyre and axle weight details. Tyres are Michelin 215/75 R16 XC Camping. I was advised that for the given axle weights the pressures should be Front 60PSI and rear 65 PSI. I then heard that Michelin had changed their general advice following I believe a discussion with VOSA and their head office. I rang them today and they confirmed that advice has changed and that whilst the front pressures will vary according to a given axle weight, the rear will now be the maximum 80 PSI. I think they said that VOSA consider that Motorhomes will generally be running at or near their maximum weight and this is the pressure they legally expect. If thats the case then I bet insurance companies will expect the same in the event of an accident etc.
I have now increased the pressures of the rear to the 80PSI stated and am off for the weekend so I am expecting a harder ride. They recommended 60PSI at the front including an allowance for weight transfer under cornering and braking.
If you have Michelin tyres it would be interesting to know if others have had the same advice. I have spoken to two different persons at Michelin and both told me the same. I am not the only one that I am aware of that have recieved this advice and logically it may well apply to other makes.
Regards, Dave


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## zappy61 (May 1, 2005)

I was given 70psi front and 80psi rear. I did think that the differential between the two was high at 10psi, anyway I have ajusted them as per the email. I haven't been on the road yet so can't comment on the ride.

Graham


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## bill (May 10, 2005)

Hello 

Until recently I ran my XC Camping at 80psi, which some on here felt to be too high, I'd based that on the max pressure marked on the tyre itself. anyway for five years and 26,000 miles I crashed and banged from a to b. Having now just changed them I found that the front tyres had worn evenly and not excessively, the rear had hardly worn at all.

Now having changed to Agilis 215/70 R15C 109Q I emailed Mitchelin to ask about pressures for my max axle weights of front 1750kg, rear 1900kg, for which they recommended 60psi for both. (This advice has been given within the last month) Wow I thought that's low. Anyway I tried it over 400 miles and found the ride so much better. Whether this is due to the pressure alone or the new style of tyres, I don't know. Probably both. The tyres did get warm but not hot. 

Mitchelin did explain that a slight increase had been added to the front pressures "due to the braking forces and shift of weight that's being exerted onto them".

I'm also interested in the advice others have had on this matter, particularly where the Agilis and similar axle weights to mine are concerned. Thanks for raising the subject

Regards

Bill


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## ingram (May 12, 2005)

I contacted Michelin a few months ago. I gave them the actual maximum permissible gross weights for my 'van. They commented that it would be better to quote pressures for the 'actual' weights after checking on a weighbridge but they gave me 'ball park' figures on the gross weight figures supplied.

They were a lot less than the door post sticker. They were 60 psi front and 70psi rear; which was much the same as the tyre website that was linked to in a previous post here. The door post sticker was in bar, but approx. 80psi front and rear. I am running at 60 / 80.

Harvey


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## 111758 (Apr 28, 2008)

*Tyre Pressures again*

Year ago I contacted Michelin told them my axle weights, Rear 1860 Front 1600 (Rapido 7087F) Fully loaded. Tyres 215/70 15C

They informed me that my tyre pressures should be F55 R60.

1/4/09 They suggest F70 R80

10/04/09 They suggest F55 R80

What ptessure should I use ?????


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## Solwaybuggier (Mar 4, 2008)

I'm in the same boat - contacted Michelin in last fortnight and, having sent them readings from a weighbridge, was advised to use 55F/65R on Agilis Camping 215/70 R15 CP, fitted to my Autotrail Cheyenne 635. I'd previously used 80 all round - on the basis probably better too high (and suffer bumpy ride and possible excess wear) than too low.

However, if I read Paul68's post right, it appears that VOSA have pressured/advised Michelin to change their stance - which is a pain, but I guess I'll increase rear pressure again to close to 80.


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## 111758 (Apr 28, 2008)

*Trye Pressures again*

Just found a sticker on my Rapido which states tyre pressures, It reads

Front and Rear 5.5 bar + / - 0.05 and

Front and Rear PSI 79.5 + /_ 1

So mine are going to be 79.5 all round.

Paul


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## ob1 (Sep 25, 2007)

It looks like Michelin and VOSA have got together to play the safety first game. In other words the tyres don't need to be run at 80psi but just in case you overload your van they are now recommending that figure. If a given Michelin tyre only needed, say 65psi, last month it stands to reason that it only needs the same now - given the same weight loading.

As for stickers on the door pillar, I've had motorhomes with GVW from 3500-5000kg which all had 80psi stickers on! The same reasoning applies in that the chassis manufacturer has no idea what weight the converter will put on the chassis, so lets play safe.

Ron


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## Chudders (Jul 5, 2008)

Well I have now driven today about 100 miles to Little Cotton at Dartmouth (Nice site). The rear tyres were at the recommended 80PSI and in honesty whilst the ride was harder it was not excessively so. It was only on minor rougher roads I was aware of trhe difference. Main roads etc did not feel much different. So 90% of journey was fine and the remaining 10% reasonable. I recently had air ride suspension fitted on rear and wonder whether that has made it a bit more3 acceptable.
Happy Easter break everyone
regards, David


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## Wizzo (Dec 3, 2007)

Got to agree with Ron (ob1). My door pillar also gives a pressure of 80psi but in my normal running weight of 2,600kg that's way over the top. From the Motorhome tyre safety booklet my pressures are correct at 49 / 50psi.

I wonder what VOSA's position would be if I were stopped and tyre pressures were checked?

JohnW


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## loughrigg (Nov 10, 2008)

This is enough to drive a newbie to drink - at exactly the right tyre pressures, of course.

I'm struggling to understand how the given tyre pressures in a handbook, on a door pillar or anywhere else, can be very much more than a guideline based on a particular tyre brand/model at an assumed vehicle loading.

Change the tyre brand/model and vehicle load and the given pressures may become irrelevant or possibly even dangerous.

For example, the pressures in my base vehicle handbook (2002 Boxer) are based on Michelin Agilis tyres. The door pillar pressures are based on (I think) Michelin Campers - a guess because those were the original tyres fitted by the converter. Without digging out the handbooks, I don't recall what the recommended handbook/pillar pressures were, but they did differ by a fair margin.

I had to have new tyres fitted at purchase (the old ones were six years old and showing cracking) and opted for a set of Vredestein's (correct size and weight index but a considerably lower maximum allowed pressures at max loading than the Michelins). Inflated to the handbook/door pillar pressures, the Vredesteins would have exceeded the max allowed full load pressure for the tyre by 15+ psi.

Having seen the door pillar pressures, the tyre fitter did inflate the Vredesteins to the max allowed pressure on the tyre wall (60 psi), but as 60 psi is the max pressure at full load, my very lightly loaded MH drove like it was on marbles.

After a bit of experimentation, I'm now running the MH with pressures of around 54 - 57 psi all round depending on the number of occupants and loading. Handling/ride comfort is acceptable at those levels and loading within the indicated weight index for the tyres.

Is that an unreasonable approach?

Mike


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## jonse (Nov 2, 2008)

*Hankooks tyres*

Had two of these fitted on the rear and the max is 65 psi and I run them at 60 as I don`t need to get any where in a hurry there fine for me, my max is 3400kg no good for any thing heavier though and some will say I am mad to use these but Adams Morey said they were OK to use . and as I don`t like to give more tax to any government than I have to, I drive purely for economy which means 50 most times and the pleasure of seeing the country side.


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## Jean-Luc (Jul 21, 2005)

Do VOSA design and make tyres NO.
Do Michelin, Hankook and Continental design and make tyres YES. 
One would expect the designers and manufacturers of any product to know more about it than a bunch of civil servants, who are they to assume one is guilty (of overloading) before trial.
BTW do they know (VOSA) that 
'An overinflated tire is stiff and unyielding and the size of its footprint in contact with the road is reduced. If a vehicle's tires are overinflated by 6 psi, they could be damaged more easily when encountering potholes or debris in the road, as well as experience irregular tread wear. Higher inflated tires cannot isolate road irregularities as well causing the vehicle to ride harsher and transmit more noise into its interior' a quote from this website. 
To my mind reduced footprint would lead to poorer roadholding and breaking performance, particularly in the wet.
Colin


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## zappy61 (May 1, 2005)

*tyre pressures*

Been running mine on 70 and 80 psi respectively since April, no increase in rattles and all seems fine.

Graham


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## DTPCHEMICALS (Jul 24, 2006)

Each journey made has variables in weight, weight disribution, road conditions etc.
If F1 teams have trouble setting tyre pressures what chance have we got.
My car has diferent rear presures when carrying 4 people to when carrying 2. I dont change the tyre pressure when I drop off 2 passengers for the rest of the journey home.



Dave P


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## RichardnGill (Aug 31, 2006)

Chudders 

Is you van a TAG axel? 

As there has been a recent change with these, but not on 2 axel vehicles as far as I know


Richard...


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## 106559 (Aug 19, 2007)

*Re: Hankooks tyres*



jonse said:


> Had two of these fitted on the rear and the max is 65 psi and I run them at 60 as I don`t need to get any where in a hurry there fine for me, my max is 3400kg no good for any thing heavier though and some will say I am mad to use these but Adams Morey said they were OK to use . and as I don`t like to give more tax to any government than I have to, I drive purely for economy which means 50 most times and the pleasure of seeing the country side.


i take it you are meaning Vredesteins, if so ignore those who think you are mad. These are good tyres from a reputable manufacturer.
By the way, my van,Sprinter 316 3,500kg- 51 psi front-65psi rear.
It's on the plate and should VOSA have an issue with that then I would invite them to take said issue up with M.B. Don't think they'd bother somehow. There does seem to be a bit of paranoia regarding tyre pressures here, if you go by the plate and it suits you then don't worry about VOSA. If you don't go by the plate then the onus would be on you to prove that VOSA recommends etc.
Me, I'll trust Merc and sod the 'wheeltappers'!


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