The tire shop where I took my SUV to have the tires replaced suggested filling the new tires with nitrogen to help prevent ...

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.

Have you ever noticed cars with mysterious green valve stem caps on their tires? If you have, you may wonder why some people choose to use them. Don't worry — a lot of people have the same question, ...