As the weather turns colder, I always get a flurry of questions from customers who say their TPMS (Tire Pressure Management System) sensors have been activated telling them that one or more of their tires has experienced a drop in air pressure. Basically they go out to their car on one of the first colder mornings of the season and the warnings start. Understandably, these drivers are worried that one of their tires might have a leak, so they call or come to the shop to investigate. Don't panic, I tell them. When the temperature drops significantly, your tire pressure can actually go down without losing any air at all. I'll skip the physics lesson, but the warmer a tire is, the more pressure it will exhibit with the "same" volume of air inside. A sensitive TPMS sensor will see a drop in pressure with a drop in temperature. So before you freak out, fill your tires to the correct pressure, and give it a day. Chances are you are in the clear.