[quote=nox1s]Pardon me and I don't think you're dumb, but you know air expands in the heat (higher PSI) and condenses in the cold??
quote]
Pardon me and I don't think you're dumb, but condenses is the wrong word. Contracts is the word.
Tire pressure changes approximately 1psi for every 10 degree F. change.
So if tire pressure is OK at 50 degree F the light should not come on until the temperature gets to 0 degrees F. approx.
But I think these sensors are not that consistent so the light just comes on when it gets cold and goes off when they warm up a little.
Fill the tires when they are cold and check them regularly. With the cost of tires being what they are we should look after them and gas usage goes up with under inflated tires.