Why Is My Tire Light On Every Cold Morning?

The Physics Of Temperature

Many don’t realize it, but air pressure in tires is affected by weather. When a cold snap comes through your town, you’ll find that tire pressure may be reduced. The result will be that an indicator pops up on your dashboard telling you as much. 

When you’ve got exceptional temperature shifts, you can see a difference in tire pressure as high as 10 Pounds Per square Inch, or “PSI”. How did things getting a bit chilly suck 10 PSI out of your tires? 

Well, for every ten degrees lost during a cold snap, a tire is going to lose about 1 PSI. This isn’t because the air has escaped the tire. Rather, the air inside the tire has condensed. Here’s an in-depth piece of writing on that.

Condensation Is Temporary, Seepage Isn’t

For the most part, this condensation is temporary. When you roll your tires on pavement with the weight of the vehicle atop them, ultimately this ends up “warming up” the tires, and they decondense. 

Sometimes, though, you can hardly tell they’ve gotten some of their pressure back. Also, in places like Wyoming where subzero temperatures can remain for weeks, even heavy driving may not return necessary pressure. 

This is because beyond condensation, there is what’s known as “seepage” as well. Cold snaps that hit quick do result in condensation; but beyond that, your tires are going to lose about 1 PSI a month owing to air “seepage”. That is: air escaping around the rim of the tire, and even through the tread itself. 

When you combine cold weather with long amounts of time spent indoors, you can see exceptional loss of tire pressure over time. If you’ve ever left a vehicle parked on its own for about a year, when you examine it, you shouldn’t be surprised if all four tires are so low they’re almost flat. Sometimes they will require inflation just so you can drive owing to cold and seepage. 

How You Should Handle Low Tire Pressure

When you’re just experiencing condensation owing to air temperature reduction, driving for twenty minutes to a half hour should correct the issue. However, you can’t correct seepage this way. A good idea is to simply cruise into a gas station nearby when you notice you’ve got low tires, and fill them with air. 

If there is no gas station nearby, a simple bicycle pump can be used for the purpose; though be advised, it does take a while, and you’ll likely be sweating by the time you’re done filling up the tire. Also, if you pump up the vehicle, or get it filled at a gas station, and the tires get almost flat again, you may have a leak or a puncture, and you should probably check with an automotive tire facility to see if repair or replacement of the tire is necessary. 

Wintertime affects vehicles in a variety of ways, not least of which being a loss in air levels. Always be sure you check tire pressure on your vehicle before driving after a cold snap. This can be done visually, and you can additionally use a tire pressure gauge to determine exact PSI. For more tips on vehicles and how weather affects them, be sure to explore our blog at Anybody’s Autos!