What is TPMS?

What is TPMS?

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TPMS stands for tire pressure monitoring system: an electronic system that alerts if tires are significantly under-inflated. In 2000, the Transportation Recall Enhancement, Accountability and Documentation Act (TREAD Act) made TPMS mandatory to enhance road safety. Among other mandates, the TREAD Act stated that it is required to have a tire pressure monitoring system in all vehicles manufactured after September 2007. 

Tire pressure monitoring systems have an important role in safe driving. TPMS helps to keep proper tire pressure which is essential for vehicle stability, fuel efficiency, and overall safety on the roads.

How does TPMS work?

There are two different types of tire pressure monitoring systems. It is up to vehicle manufacturers to decide which one to use. 

Indirect tire pressure monitoring system

Indirect TPMS works with the vehicle’s anti-lock braking system (ABS). It doesn’t measure directly the pressure of each tire but utilizes the rate of wheel revolution to determine the air pressure. If wheel speed sensors notice that one of the vehicle’s tires rolls at a different speed than the others, the tire pressure indicator illuminates. 

Usually, indirect TPMS is the more economical option of the two types of tire pressure monitoring systems. It is good to note that indirect TPMS needs resetting after tire rotation and inflation. 

Direct tire pressure monitoring system

Direct tire pressure monitoring system measures the air pressure of each of the tires. Each tire has a sensor, and the data from their monitoring systems is transmitted directly to the vehicle’s dashboard. If the air pressure drops 25 % under the vehicle manufacturer’s recommended level, the TPMS indicator on the dashboard lights up. 

Direct TPMS gives more accurate data compared to indirect TPMS. Also, it doesn’t need resetting after inflation or tire rotation.

Benefits of tire pressure monitoring systems

A tire pressure monitoring system makes it easier for you to notice if there are significant drops in tire pressure. Maintaining correct tire pressure is essential for safe and efficient driving. Low tire pressure can create unsafe driving conditions – by monitoring the pressure you enhance road safety. 

Under-inflated tires are more prone to tire blowouts, being a traffic hazard. When your tires are properly inflated, the vehicle is more predictable, the steering is more responsive, and the braking distance is shorter. Also, properly inflated tires wear evenly, which helps you keep tires quiet

In addition, TPMS contributes to better fuel economy. Driving with under-inflated tires increases rolling resistance, and thus the vehicle consumes more fuel. By noticing low tire pressure and inflating the tires, you make your vehicle more fuel-efficient. You can also reduce fuel consumption by using tires with high fuel economy ratings

What to do when the indicator light comes on

When the tire pressure monitoring system’s indicator illuminates, it tells that tire pressure has dropped significantly. Check the tire pressure for example in a gas station, garage, or tire store. You should check the pressure of all four tires. Inflate the tire – or tires – that have lost the correct pressure. When the air pressure is proper again, the indicator’s light should go off. If it doesn’t, it might need resetting. 

A sudden drop in tire pressure can happen also because of a tire blowout. In case of a blowout, change the damaged tire to a spare tire. Note that the spare tire is for temporary use only and might not have TPMS on it. You should replace it with a new tire as soon as possible. 

Other signs of low tire pressure

TPMS is a useful tool for monitoring tire pressure. However, tire pressure sensors only register significant tire pressure drops, meaning that they do not indicate slightly under-inflated tires. Here are some signs that tell the tire pressure might be too low: 

  • Unusual tire noise. When tire pressure is too low, you might hear a thumping noise while driving.
  • Edge wear pattern. Under-inflated tires tend to wear faster on the edges of the tire.
  • Increased fuel consumption. If you need to fill up more often than usual, it might be caused by too low inflation pressure.
  • Decreased responsiveness. It is more difficult to steer and slow down when tire pressure is too low. You might also feel that the vehicle has less grip.

Check your tire pressure regularly

Driving with correct tire pressure helps you to better control your vehicle, consume less fuel, and make your tires last longer. Note that TPMS does not substitute manual tire pressure checking. We recommend checking tire pressure at least once a month. It is good to measure tire pressure also when you notice some of the signs mentioned above. Check the tire pressure regularly to extend the tire lifespan and enhance safety on the road.