535i M-Sport touring (wagon) on 18" summer RFTs, square setup.
I run 2.4 bar (35 psi) front and 2.65 (38 psi) bar rear for normal use. Gives the best run-flat tyre performance, no weird RFT characteristics. Run same setting pressure on 17" winter RFTs in average winter temperatures.
Interesting you posted this today, as I have just been out (ambient temperature is dropping fast up here below 7C) and wet, felt the first bit of RFT steering corruption. My thoughts were "cold tyres, lower pressure". So when I came in I checked the pressures, and even after 30 miles driving the tyres were cold. Were at the setting pressures, not working pressure. After cooling down for an hour the pressures are reading low as I'd expect. Was about 15C when I last set the pressures. Will be resetting pressures as soon as the rain stops. Already had my compressor running, have a tank of air ready.
So cold stiff walled tyres, not warming on the run, clearly show my normal setting is just high enough, anything less and tyre performance deteriorates and corrupts the drive.
HighlandPete