Tyre pressure too high?

Happy to provide requested advice. First take the motorhome to a certified laboratory to check the actual temperature in the motorhome over a range of ambients. Next get appropriate graphs from the temperature gauge manufacturer to determine accuracy of the instrument. Finally, work out the difference between the observed temperature and what the gauge is telling you. Armed with that information, if it’s too hot inside then turn it down.

After you read my posts, you can conclude yourselfes that front 1850kg + 10% = 2035kg, and rear 2000+10% = 2200 kg, yust need those pressures.   In my spreadsheet , in case of only MPAW given , I add front 5% because seldom overloaded, and rear 18% to cover most likely overloading.  

So search back in your list next.

Front 1850+5%= 1942.5 kg. 

Rear 2000+ 18% or 2000/0.9 = 2222kg

Calculated back that you tyres have maxload of 1030 kg is loadindex 109.

Filled that in in my calculator, wich uses formula that gives higher pressure then the officially used, came to 4.3 bar front , and 5.2 bar rear. 

5.2 is not allowed on your 8 plyrated tyres, or they must be CP tyres, but to laws of nature it is best to use that 5.2, as long as you did not weigh. 

If you give length and wheelbase of your motorhome, I can determine a more realistic weightdivision F/R, and give advice for that. 

Advice is for cold measured, this is when temp in and outside the tyre is the same, so when not driven long enaugh and no external factors like sunshine on tyre. 

Advice is determined for outside temp of 18 degrC( some write up to 21 degr C. 

So extreme hot outside you have to fill higher pressure, so dont blead down, if you measure that higher cold pressure on a hot day.

As has been said, take the motorhome to a weighbridge when fully laden including driver and passenger(s), fuel, water and all consumables and write down front and rear axle weights. For sure, there may be a small imbalance between offside and near side so a 5-10% allowance can be added to the weights. Check the tyre manufacturer’s data sheets and inflate when cold. Not difficult.

Continental Vanco tyres are very popular and if you have these you should ignore the maximum inflation pressure embossed on the tyre as it’s for the american market and irrelevant in the UK.

Having tried unsuccessfully to get the pressure monitor reset at a Peugeot garage (not main dealer) I just live with the low pressure warning. It has been said on other forums that main dealers will not recalibrate the pressures to lower values than those printed on the door pillar.

If you have Continental or of that group, you find 2 pressures on sidewall ,  1 direct behind the 109/107 Q   65psi.

And on thevother side of sidewall ( 6 o clock) 10 psi higher " maximum inflation pressure" 

The 65 psi is then the reference pressure cold , and the 75 psi is the maximum allowed cold pressure. 

So then Continental allows you the 5.2 bar behind. 

Other brands in C group

Viking , uniroyal, barum, vanco, and some more, and they all give often the 2 pressures. 

Seems like I keep repeating myself. I can’t speak for other makes but for Continental Vanco tyres, Continental tell you to use the pressure charts which correlate to axle loads and ignore what’s stamped on the tyre. Hence you have to go to a weighbridge if you want to reduce the pressures.

But as long as you did not weigh yet , you have to use pressures on the high side, to prefent once tyre overheats because pressure was to low for the real but unknown weight and speed used. 

To high only gives discomfort and bad gripp, but never unsave for the tyres. 

Topicstarters advice based on his MPAW's ( F 1850kg, R 2000kg, seached back in list , gives F3.75 , R 4.3 bar. 

Asume has the time to weigh and his weights are F 1750kg and R 2200 kg, yes overloaded vehicle and rear axle, but happens often enaugh. 

Then its possible that his tires already are damaged by overheating. 

And that is what I try to prefent with my advices.

I actually contacted  Peugeot customer service and was told that the pressures could not be changed, I challenged that as Continental had supplied me with a chart which contradicted the Peugeot figures, they changed their minds and told me to contact the Peugeot dealer in Taunton for the recalibration to be done.

For various reasons mainly time and location, I didn’t get it done in the end but still have the communication from Peugeot.

Probably your Peugeot-dealer will also make it diffucult, and first say its not possible,

Its not that its not possible, but they dont want us users to know better then them. 

You have to know who is boss,and if the king says the earth is flat, its flat. 

So you have to overwhelm them with facts.

And those are 

1. You weighed per axle, or better axle-end, in the loading you go on tripp, so all the persons , freight, water , battery's , gas-bottles, dogs, parrot..... or didn't you?

2. You added 10% to the axleweights for reserve

3. Then looked those weights back in the right pressure-loadcapacity-list for your tyres.

But this shows why they make it that difficult.

Enaugh weigh with not everything in it, and take no reserve.  And nowadays they can be held responcible at least partly, when something tyre-related happens.

I was quoted several hundred pounds when I had my Marquis. I just experimented to find the lowest pressure without triggering the dashboard warning.