Thanks for the info. New BMW's have metal valve stems and individual Beru transponders inside the wheel monitoring the actual pressure. This system doesn't simply rely on using ABS sensors and monitoring wheel rotation. This new system is particularly important with run flat tires. Think about it, with the old system and run flat tires, you could have zero air pressure but because the rolling resistance of the tire might not have changed significantly then the flat tire monitor wouldn't go off. The new systems individual pressure sensors will however tell you if your run flats are at zero pressure.

I'm just curious about this since BMW's metal valve stems come with different caps then the older rubber valve stems and never before did I hear that changing the caps would have any affect.

• Valve stem caps question on E92 wheels (pic) - mgruber 2008-03-21 01:59:17 (143 views)
  • Re: Valve stem caps question on E92 wheels - 74u2 2008-03-22 19:12:28 (78 views)
    • Re: Valve stem caps question on E92 wheels - mgruber 2008-03-22 19:24:23 (86 views)
      • Re: Valve stem caps question on E92 wheels - 74u2 2008-03-22 20:01:02 (85 views)