What's the best air pressure, front and rear, for BF Goodrich g-force Supersport A/S 205/50/16 on a 2004 MCS?

 

I find the MINI recommendation for he 195/55-16s is a good starting point. That was 30psi for a light load (35 for a heavy load) according to my 04 manual.

A friend of mine has a theory about tire pressure which I've been experimenting with. His theory is the correct pressure gives you an even running temperature across the tire. A high pressure heats up the centre, a low pressure heats up the shoulders more. I've been using a little IR thermometer to measure the temperature of the tires when they're hot and try to even out the temperatures by fiddling with the pressures.

That's worked for most tires I have.

 

It's not just his theory.

I use a probing pyrometer at the track after each session to measure tire temps and adjust pressure accordingly. IR thermometers don't work as well since they measure the temperature on the tire surface and that is less accurate because those temperatures change (cool) much more quickly once you stop moving.

 

I poke the IR thermometer into the grooves of the tire to get a measurement closer to the core temp of the tire, it cools down much slower in there.