BOISE – With plenty of wet and freezing weather on the way, properly inflated tires are more important than ever.  All new vehicles are equipped with Tire Pressure Monitoring Systems (TPMS) to reduce the risk of driving on dangerously low tires.  But how accurate are they?

AAA recently tested 11 passenger vehicles – 2022-2024 models including sedans, pickups, and SUVs – equipped with “direct” TPMS that use air pressure sensors mounted in each wheel.

In AAA’s research, the monitoring systems were generally accurate, with the average difference between displayed and actual tire pressures between 1.2% and -1.5%, depending on tire location.

But don’t throw away your manual tire pressure gauge just yet.  AAA’s new study also shows that when tires were underinflated to 75% of manufacturer recommendations, the amber warning light on the dashboard illuminated for just five of the eleven test vehicles.  Five of the six remaining vehicles alerted drivers when tires were between 70-73% of recommended pressure.

“A tire with the correct air pressure improves handling, braking, and fuel efficiency while reducing the chances of a blowout that could cause a serious crash,” says AAA Idaho public affairs director Matthew Conde.  “The technology has come a long way, but it pays to occasionally double-check that the readings are accurate.  After all, your tires are the only part of your car that touches the road, and they need to perform consistently, especially when the weather turns.”

AAA urges drivers to use displayed data in the instrument panel to monitor tire pressure and re-inflate tires to the vehicle manufacturer’s specs as needed.

AAA’s tips for driving in wet weather

  • Remember that cold weather reduces the current air pressure in your tires
  • Drive with your body in an elevated, alert position rather than a “cruise” posture
  • Make sure lights, tires and windshield wipers are in good working order
  • Avoid sudden acceleration, braking, and sharp turns to help prevent a skid
  • Increase following distance by 2-3 times in bad weather (6-9 seconds)
  • If you can’t see fog/center lines or the road ahead, pull over somewhere safe and wait for the storm to pass
  • Never use cruise control in wet weather and foggy conditions

“Roads are especially slippery during the first 10 minutes of a storm, when oils and other products rise to the surface,” Conde said.  “As the saying goes, slow and steady wins the race.”