Issues with tires contribute to approximately 11,000 crashes annually, according to the National Highway Traffic Safety Administration. Many of these crashes occur during the coldest months of the year. Why? Because dropping temperatures can impact your tires — and as a consequence, the safety of your vehicle.
To understand how dropping temperatures impact your tires, you first need to know how temperature impacts air volume. When the temperature increases, the gas molecules start to move faster and take up more space. When the temperature drops, they slow down and require less space. That means that in a space with a flexible barrier around it — like a tire — dropping temperatures will cause the air pressure inside the tire to decrease. In fact, for every 10 degrees the temperature decreases, a tire can lose between one and two pounds of pressure.
So what exactly can happen if you drive with underinflated tires?
- Your car becomes less responsive. Underinflated tires are more flexible than they’re supposed to be for driving. This has an adverse effect on the vehicle’s handling and makes it harder to stop. All things considered, it makes your car less safe to drive.
- You risk a tire blowout. Because the tire doesn’t contain sufficient air, there’s increased friction. This can cause a tire blowout — and that in turn can lead to a serious accident.
- You get lower mileage. With more friction on the tires, your car has to work harder, which means it consumes more gas.
- There’s increased wear and tear. Even without a major problem like a blowout, there’s still going to be a lot of unnecessary wear and tear on the tires. As a result, you’ll have to replace your tires sooner than if they were properly inflated.
Your car’s recommended tire inflation PSI (pounds per square inch) is listed in your owner’s manual; it should also be noted on a sticker inside the door jamb on the driver’s side. You should check the pressure of all tires — including the spare — monthly. In addition, it’s a good idea to check it after any significant changes in temperature. Use a tire gauge, which you can purchase at a hardware store or online, to measure the PSI. It's best to do this when the car hasn’t been driven for three hours or more; tire pressure increases due to the heat caused by friction when driving, so you won’t get an accurate reading if you check immediately after driving. If the pressure is low, go to a gas or service station and add air to the tires.
Note that the Consumer Reports article titled “Tire Safety Checklist: What to Do Before Your Next Road Trip” warns that when your Tire Pressure Monitoring System (TPMS) light comes on, it’s not simply a reminder to check tire pressure. Instead, it’s an indication that your tires have already lost 25 percent or more of their pressure and therefore require immediate attention. In other words, you need to inflate your tires to the correct pressure immediately.