JDN

Then that brings up more questions, CRR. What about the different tires on front and rear in the SP, mismatched tires and tires that are more worn than others? Obviously, I am having a hard time getting this concept through my cranium.

pennetta

I think there are variations in diameter of even the same brand/size tire. My car has the staggard setup which runs different sized tires front to back. I think the system utilizes the anti-lock mechanism/electronics, and while initializing, just averages each individual wheel rotations over a certain distance. If the a tire deviates from this average then it flags it. That why you don't have to drive only in a straight line while it initializes.
It is important with runflats since they don't look flat when they are deflated because of the stiff sidewall. It happened to one of my tires and you could not tell which tire it was until you find a nail or check the individual tire pressures.

JDN

Thanks, pennetta. That's a reasonable explanation until somebody nails it for sure.