And not to forget or teach anyone to suck eggs, but these are COLD pressures. Handbook defines cold as standing for at least 3 hours or driven less than 1 mile. A hot tyre will measure 4-6 psi more.
If tyre pressures are that critical I wonder why car makers don't give an ambient temperature (say standard pressure at '20degC' like most other things) and some kind of 'de-rating' figure to allow for ambient being below or above 'standard ambient'. Even in the UK the ambient temperature can vary from -10degC in winter to 35degC in summer (most countries it varies way more than that) - and if the tyre is directly in the sun in our summer the sidewall can reach probably 60degC which would make quite a difference to the pressure in the tyre. I bet a tyre driven for 3 hours in winter would still not get very warm, nowhere near as warm as a tyre standing on a hot tarmac drive in midsummer.
there is only 1 psi difference in front tyre pressure between 2 passengers and luggage and 5 passengers and luggage, and 3 psi on rear tyres. A change in ambient temperature would make more difference than that.
one of the advantages of nitrogen filling is that the temperature does not affect pressure so much (the other is that because nitrogen molecules are bigger than 'normal' air molecules the pressure leaks away more slowly)
the date your tyre was manufactured is actually shown on the tyre. The age of a tyre may be determined with the help of the DOT number. Any tyre over 10 years old, even with a lot of tread should be changed due to deterioration of the rubber compound with age, irrespective of miles traveled.
you will find 'DOT' and a string of letters and numbers on the sidewall of your tyre -
example - DOT EB V3 BRD
2305The DOT numbers have had four digits since the year 2000. Since the 1st of January the DOT numbers have been stated in last four digits of the string . The first two digits state the calendar week; the last two digits indicate the production year.
Example:
2305 = 23rd calendar week 2005
