With the latest “Polar Vortex” to sweep across the Prairie, getting machines to operate in those frigid temperatures usually requires some additional effort. And if you climbed into your late-model pickup truck and noticed a tire pressure warning light come on, you’re not alone. According to General Motors, the first hard dip in temperatures each year sends a flood of vehicle owners to tire shops all across North America to check out the problem.
GM’s latest communiqué talks about why it happens. It’s simple stuff, but a good reminder.
“The polar plunge that has chilled much of the nation does more than bring out ice scrapers and antifreeze,” reads the press release. “It can trigger vehicles’ tire pressure monitoring systems overnight, sending nervous drivers to dealers and service centers.
“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 1 pound per square inch (psi), said David Cowger, global sub-system manager for tires in General Motors’ Tire and Wheel Lab. On top of that, tires slowly lose air anyway – the equivalent of between .25 and .5 psi per month – because air passes through rubber.
“‘So if you last checked your tire pressure a few months ago when it was 70 degrees and now it’s 20, a tire with a recommended psi of 35 could be down to 27 or 28 and set off the TPMS warning,’ said Cowger. ‘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), said Cowger. Under-inflated tires can wear out prematurely, negatively affect vehicle handling, reduce fuel economy and overheat, leading to blowout.
“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 a tire’s pressure drops 25 percent below its recommended psi.
“Check tire pressure at least monthly with a quality tire gauge, and when the vehicle has been driven less than a mile. Tire inflation increases 2-3 psi when the tires warm up during driving.”