Regulations about fitting tyres and the use of tyres - Tyre pressure monitoring systems (TPMS) are now obligatory

Tyre pressure monitoring systems (TPMS) are now obligatory

Regulations and Safety Published the 03/12/2012 by Jake

From 1st November 2012, all new car models will be equipped with a Tyre Pressure Monitoring System (or TPMS). From 1st November 2014 all new passenger vehicles will have TPMS installed. A step forward for safety and the environment.

Surveillance system for tyre pressures Copyright © : Continental

The widespread use of Tyre pressure monitoring systems and ESP (anti-skid system), along with tyre labelling are part of the measures decided by the European Commission in 2009 to improve vehicle safety. These come into effect in 2012.

TPMS (Tyre Pressure Monitoring System) became obligatory for all new type passenger vehicles (M1) in November 2012. Starting November 2014 it is obligatory for all new passenger vehicles.

A measure to promote safety and the environment.

If the widespread use of tyre pressure monitoring systems aims to improve safety, it also aims to reduce the environmental impact of traffic at the same time. Indeed, many studies have shown that under-inflated tyres lead to excessive fuel consumption and premature tyre wear. During its annual survey, Bridgestone noted that two thirds of motorists in Europe drive with under-inflated tyres. The tyre manufacturer has calculated that this accounts for 2 billion litres of wasted fuel and 4.8 million tonnes of additional CO2 emissions.

Two pressure control systems

Two technologies are currently used:

  • Indirect TPMS: connected to the ABS and the ESP, the device measures wheel rotation speed differences. A speed increase in one wheel indicates a reduced diameter, therefore a pressure loss in the tyre.  This system does not have a bright future, since it is unreliable and does not provide exact tyre pressure measurements. 
    Advantage: Inexpensive system.
    Disadvantage: Inaccurate results, the ABS detector must be replaced if broken.
  • Direct TPMS: The device uses an electronic sensor fitted to the tyre valve which measures the tyre pressure and sends the data by radio waves to a receiver that displays the results on the car’s dashboard.
    Advantage: Accurate and instantaneous measurements. The system is used in the United-States.
    Disadvantage: Costly, takes responsibility away from the driver.

The American experience is not totally conclusive.

The tyre pressure monitoring system has been mandatory in the United States since 2006. An alarm is triggered on the dashboard when the tyre pressure drops below 25% of the manufacturer’s recommended pressure. Tyre manufacturers say this threshold is too high and have conducted a study that shows that 70% of tyres are damaged beyond repair by this stage.  Another study has revealed that with the widespread use of TPMS, drivers check their tyre pressure less often than before. Explanation: They wait for the alarm to trigger before re-inflating their tyres, which is not really the objective.

Precautions to be taken when changing tyres

tpms_siemensCopyright © : Siemens
The pressure sensor is easy to operate.  The air pressure acts on a piezo-crystal membrane through a small hole. The pressure difference is then converted into a voltage difference and the measurement is sent to the receiver by a radio signal at a frequency of 433 Mhz (in Europe). The sensor operates with a small battery.  Please note that sensors are very fragile. When you change your tyres, don’t forget to tell your specialist about the sensors. It will prevent them from being damaged or lost!

Read more:

Tyre pressure monitoring systems anticipated for the cars of 2012

Use your phone to check you tyre pressure!

How good are tyre pressure sensors?