what is air pressure for tyres measured in?is it pci?What air pressure would a peugeot 306 need aprox?its a small enough car?

they measure it in PS l or BAR(dont know what that means):) but the recommended pressure for a car depends on the type of tires is on it. but the pressure recommendations are usually printed on the tire its self look around the tire edge close to the wheel.

Click through on the link below, there is pressures for many peugeot models there, they are in psi by the way.

http://thetyrepressuremonitor.com/tyrepressures_peugeot.html