He went on to advocate setting tyre pressure values when hot. Michelin: Make sure you have the correct tyre pressure and remember to check the pressure on cold tyres to get the most accurate reading. Others mentioned this apparent error but have the comments disappeared?

a poor response due to the failure to educate the question raiser on the importance of checking tyre pressures and going on to encourage him to seek redress from the supplying dealer.

I found it rather strange that HJ was implying the tyre pressures are given for tyres at working temperature. Every car I have had indicates the pressure for cold tyres.

VERY lighrheartedly,

Had you checked it before?

I've not checked my handbook for the 325d, but I was also always told that pressures should be checked and adjusted at cold, rather than hot.

A surprising error from HJ.

Oh, and I only went through the 'quick start' guide when I bought the car. But the whole manual is heading on for 'War and Peace' !

Does the advice for checking when hot not come from the fact a lot of people now will not do the checks at home but when out at the petrol station and the tyres being warm rather than cold?

Tyre pressures can vary considerably during a journey - and then even more if ambient temperature fluctuates.

As a self-confess anorak, I sometimes leave my TPMS display as the dashboard display - they register the "cold" pressures within about 1/2 mile and will go up 0.1 bar (1.5 psi) just pootling around town - long motorway runs will put it up another 0.1 bar but fast runs on dual carriageway with lots of roundabouts will see it go up yet more due to braking/cornering from high speed - not talking illegal speeds here either.

Cold pressure setting is the only consistent way to do it.

I think the issue that some of us have is that HJ appears to be saying that the quoted 'normal' pressures should be when warm.

From the question : They should be 38psi front/35psi rear at normal loads

From HJ's answer : Remember, pressures rise as heat gets into the tyres so that 38/35 is the hot pressure

Whereas 38/35 should be the cold pressure - or at least that's what (it seems) we all learnt back when Noah was a lad !

Sorry Avant but you are misreading HJ's reply, correctly quoted by the OP. HJ wrote that 38/35, i.e. the pressures given by Audi, are the hot pressures, not the cold pressures. It follows, according to his logic, that the pressures have to be checked when the tyres are hot. Potentially dangerous advice since this could result in a serious under- inflation of the tyres if followed.

Tyre pressures?--ok hands up all those who

1) Check all their tyre pressures once a month( including spare-if they have one)

2) Never check their tyres

3) Only use a tyre pressure pump when they suddenly discover they have a flat.

I check my cars' tyres first thing in the morning, if possible I prefer to do it on a dull day but if that's not possible I take into account that the two which are parked outside with their sides exposed the early morning sun will differ by 1-3lbs and adjust them accordingly.

I check the tyre pressures on all 3 of our cars on the first weekend of every month. Along with oil, coolant, brake fluid, PAS fluid (though that's only on the Shogun, both BMWs have EPAS). At the same time, I have a feel on the tread for depth, and a reasonable inspection for cuts, nicks, bulges, etc.

I do the same with cold tyre pressures, coolant, PAS fluid and washer fluid (double strength in winter) - not the oil as it's all electronic and no dipstick and no brake fluid as it's buried under half the engine so is a dealer specialist job every 2 years/20,000 miles (yes, seriously!) - tyres are measured at 6 places across each tyre 3 times/year and logged (changed at 4mm for the winters and 3mm for the summers).

I recall that my last three new cars have had tyres set to high load pressures at delivery.

Edited by RT on 27/05/2016 at 08:02