Tyre Pressures

please describe how a manufacturer/converter can assess the load on each axle (without having knowledge of what or who is in the vehicle) and therefore the required pressure?

an empty 6 berth van with just a driver, might weigh half a tonne or less than one fully occupied and a loaded garage

...and what about of an owner switches from, say, michelin to Continental or Pirelli...where the same load might result in different recommended pressures.

so, instead of referring the owners to the tyre manufacturers for a proper safety driven recommendation based on real data (axle weights) they come up with a one size fits all....except it doesnt

so, who knows best.....someone like bailey or swift, who know nothing of the specific customer tyre loading, or the tyre manufacturer who has all the pertinent data?

please describe how a manufacturer/converter can assess the load on each axle (without having knowledge of what or who is in the vehicle) and therefore the required pressure?

an empty 6 berth van with just a driver, might weigh half a tonne or less than one fully occupied and a loaded garage

...and what about of an owner switches from, say, michelin to Continental or Pirelli...where the same load might result in different recommended pressures.

so, instead of referring the owners to the tyre manufacturers for a proper safety driven recommendation based on real data (axle weights) they come up with a one size fits all....except it doesnt

so, who knows best.....someone like bailey or swift, who know nothing of the specific customer tyre loading, or the tyre manufacturer who has all the pertinent data?

..I would think in the case of the M/van we had ,them ,  as the handbook stated they worked with the tyre company 

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there is no point whatsoever in a 'MV handbook' stating recommended pressures unless it provides a table for specific axle weights and the owner actually weighs the van, so as to make use of it

a van like ours has around a tonne of payload (MIRO approx 3250, MTPLM 4250) so that gives a huge variation in actual running axle weights depending if the van is very lightly loaded or ''....

so, a manual with one 'recommendation' is pointless.....

... yet again some one questioning a manufacturers figures which if not correct would leave tham open to litigation

Not so JVB.  The advice given by the manufacturer is just that - advice.  It is the responsibility of the driver to ensure the safe operation of the vehicle.  If a lower or higher tyre pressure is chosen and is thought to have caused an accident the prosecution would have to prove that the choice was wrong in all the circumstances.  

Moving on, I base our MH tyre pressures around the advice received from Michelin based on the actual axle weights.  I also use temperature as a guide.  A quick walk around the van after about 10 miles driving touching each tyre tells me a lot.  The tyres should be comfortable warm about 45-50 deg C.  Too hot indicates stress (too much flexing), and too cold indicates too hard.  

..You are saying that the TPs that were given in a handbook for each model is not correct? 

The user and all related content has been Deleted User

No JVB I'm saying they are a guide.  

Write your comments here...All vehicles then?

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a hand book guide might be better served if (as a minimum) it suggested a range of pressures....along the lines of 'empty' or 'full' etc....

with such wide ranging allowable van weights, a single handbook recommendation can only be 'right' in one circumstance...

the thing is, without the handbook explaining which particular circumstance, the poor old customer has no chance....

Generally speaking yes, but I'm sure there will be quite reasonable exceptions.  

...So our car handbook with tyre pressures for our vehicle are not really correct? that would be interesting to accident investigators,or when pulled over for roadside checks

Generally speaking yes, but I'm sure there will be quite reasonable exceptions.  

...So our car handbook with tyre pressures for our vehicle are not really correct? that would be interesting to accident investigators,or when pulled over for roadside checks

...but dont they say 'laden', 'unladen' etc?

om sure my old Audi handbook had differing recommended pressures based on load or number of occupants.

dont see why this cant be used for MH...though basing on actual axle weights is far better