The polar plunge that has chilled much of the nation does more than bring out ice scrapers and antifreeze. It can trigger a vehicle’s tire-pressure-monitoring system overnight, sending nervous drivers to dealers and service centers.
For example, about 20 customers visited a Chevrolet dealership because their tire-pressure-warning icons were illuminated. Here’s why a cold snap affects tire pressure and sets off the tire-pressure-monitoring system (TPMS) warning lamp.
For every 10-degree (Fahrenheit) drop in temperature, tire air pressure decreases about one pound per square inch (1 psi). In addition, tires slowly lose air anyway – the equivalent of between .25 and .5 psi per month – because air passes through the rubber.
If you last checked your tire pressure a few months ago – when it was 70 degrees – and now it’s 20 degrees, your tires with a recommended psi of 35 could be down to 27 or 28 and set off the TPMS warning. It’s very common when the first cold weather arrives.
Unless there are issues such as punctures or damage, the TPMS light will turn off once the tires are properly inflated.
It’s important to keep tires inflated to their recommended psi (found on a placard on the driver’s side center pillar or door edge). Under-inflated tires can wear out prematurely, negatively affect vehicle handling, reduce fuel economy, and overheat, potentially leading to blow outs.
Tire-pressure-monitoring systems have been required on new vehicles since 2007. The National Highway Traffic Safety Administration requires the TPMS to display an alert when tire pressure drops 25 percent below the recommended psi.
If your vehicle is equipped with a tire-pressure-monitoring system, check individual tire pressure readouts in the driver information center and re-inflate them to the recommended psi as necessary. Check tire pressure before you drive when the tires are cold and then again after a trip.