Q: My tires are feeling low. Is it OK to put air in them during the winter? Someone told me that filling tires in the winter can lead to water in the tires because of moisture in the air pump. A: Yes.

If you've ever noticed green-capped stems on tires in a parking lot and wondered why the car's owner chose them, you're not alone. It's a popular question, and one many people answer incorrectly.