Fwiw...

[pastorbrad]

..if you have or were considering those little valve stem caps which "alert" to low tire pressure (they come in different pressure settings and show a yellow or red band if you're underinflated), think again. They don't last...and when they fail, they gently let your tire deflate when you least expect (like, when parked during a long evening). Thought I'd picked up a nail or the sensor had failed but...