Of all features in a vehicle, tires are one of the most important to maintain. Incorrect tire pressure can affect a vehicle’s handling, braking, ride comfort, tire life, fuel economy and the environment. This can lead to tire failure including a tire blow out or tread separation. The tire pressure monitoring system (TPMS) primary function is to make the driver aware of the state of tire pressure within the wheels. Drivers are beginning to associate the TPMS warning symbol as “tires need air,” but drivers should also regularly check the vehicle’s tire pressure to be safe on the road.

What is TPMS?

Since 2008, the TREAD Act requires all passenger vehicles in the United States to be equipped with TPMS. The TPMS primary function is to make the driver aware of the state of tire pressure within the wheels. Under normal system operations, the TPMS system will alert the driver when one or more affected tires’ pressure in pounds per square inch (PSI) falls below 25% of what is listed on the placard. When the tire sensor indicates “low tire pressure,” it sends a radio frequency (RF) signal to the electronic control unit (ECU) on the vehicle that determines if the pressure is below the threshold, which then will indicate a TPMS symbol or position-specific display, depending on the vehicle.

Tire Inflation and TPMS

Having the correct tire pressure for a vehicle is crucial for safety on the road. The top three reasons why tire maintenance matters are: safety of drivers on the road, extend the life of tires, and increase fuel economy.

• Before TPMS, flat tires and blowouts contributed each year to more than 78,000 crashes, 10,000 injuries and 400 fatalities, according to NHTSA.
• NHTSA estimates that TPMS reduces the chances of having one or more severely underinflated tires by at least 56%
• In a 2011 study, TPMS was estimated to save $511 million in fuel costs.
• Drivers can improve their gas mileage by up to 3.3% by keeping tires inflated.

Pressure within a tire can change for a number of reasons including temperature changes and tire aging.

• For each decrease of 10ºF in ambient temperature, tire pressure changes about 2% of 1 PSI
• During normal driving conditions, tires lose about 1.5 psi per month.
• It is estimated that 90 people die and an additional 3,200 are injured each year in crashes because of tire aging.

How to Measure Air Pressure

It is important for drivers to check the vehicle’s tire pressure at least once a month for best safety practices. The recommended tire pressure for a vehicle is found in the vehicle placard and in the vehicle owner’s manual. Drivers should never rely on visually inspecting a tire, always carry a tire pressure gauge in a vehicle to measure the PSI.

This article was also featured in Simplifying Service, from Babcox Media