TPMS (Tire Pressure Monitoring System)

A Tire Pressure Monitoring System (TPMS) is a safety feature that automatically monitors tire pressure. There are two main types:

The two technologies

1. Indirect TPMS (iTPMS): This system uses the vehicle's anti-lock brake system (ABS) wheel speed sensors. It infers low pressure by detecting that an under-inflated tire rotates at a slightly different speed than the others. It's less expensive but also less accurate and cannot detect when all four tires are losing pressure slowly and equally.
2. Direct TPMS (dTPMS): This is the more common and accurate system. It uses a small battery-powered pressure sensor inside each tire (often part of the valve stem) that directly measures the pressure and temperature. It transmits this data wirelessly to a central control unit, which displays it to the driver.

Safety and consumption

The importance of TPMS is twofold. For safety, it provides an early warning of a puncture or a dangerously under-inflated tire, which can prevent blowouts and loss of control. For efficiency, it helps maintain correct tire pressure, which is crucial for maximizing fuel economy, ensuring even tire wear, and optimizing vehicle handling.