How come when my front tires were 8 psi low and the back tires were 10 psi low I did not get a low pressure warning? I know the Owners manual says it will warn for significant pressure lost.I would think 8-10 psi would be significant. Maybe it needed to be reset for some reason. I have a 08 335i with run flat tires 225/40-18 front,255/35-18 rear. I aired them up and some of the road noise went away,but still has some slight road noise, typical of run flats. I won't be using them the next time around.