Why does my Tire Pressure Light come on when it’s Cold out?

“Why does my Tire Pressure Light come on when it’s Cold out?” We’re going to try to answer that question for you today. Welcome to Mercie J Auto Care where compassion and craftsmanship come together. I’m Rick Smith Master certified technician. First of all I’m going to tell you I fully admit that I don’t know what it’s like to be cold. We’re here in the Phoenix area and cold for us is 40°. No matter where you live, when you have a temperature change, your tire pressure light will often come on. Think about it this way, you have a balloon set it out in the sun, it expands. Put the balloon in the refrigerator and it will contract. That’s because with the change in temperature, it also changes the air pressure, either increases or decreases. Here is a little tip on how to set the tire pressure right regardless of what time of year it is. Look on your door or in your door jam, you will have tire pressure specifications. If you read it carefully, it will say this is your cold tire pressure. That is the pressure the tire should be at when the car has sat at the overnight low. That means whenever the temperature is the lowest and the car hasn’t been driven. There’s been a lot of studies done but Nissan made it very simple. They said typically when a car comes in the shop it’s been driven around a little bit you’re going to set the tire pressure at about 3 to 4 psi higher than what the door says so that way when the overnight low happens, you’re actually at that right pressure. I hope it makes a little bit easier for you to decide what your pressure should be and I hope you understand now why your pressures change in your tires. If you’re ever nearby our auto repair shop and have a concern about your tire air pressure or TPMS Light coming on, stop in and we can check it out for you. Thanks for watching until next time blessings to you and safe travels.