Is that what Nitrogen in tyres was supposed to eliminate, less change in volume with relation to temperature.
Also explains why the 3.2 was a little unsettled leaving work on Tuesday in -4c, after 10 mins or so back to normal.
That's the theory, and why dry Nitrogen is used in aircraft tyres. ..... One of the biggest constituents of "normal" air is water vapour, and it changes volume with temperature by a large degree, it also condenses out, then freezes, at low temperatures. As aircraft tyres are subject to temperatures of -40 odd C at altitude, and they don't warm up much in the descent, IF water vapour was allowed into the tyres it would be a frozen lump at the bottom of the wheel at the point of touchdown, at which point the wheel is still stationary ... it then, very rapidly, gets spun up to a high rotational speed .... that lump of ice would cause MAJOR imbalance and SEVERE vibrations !!! (been there, got the T-shirt.... tyre was severely damaged.. but we expected it ..
This was a C130 tyre which is HUGE )
I guess car tyres suffer the same, but to a far smaller degree, due to the much lower volume of air.