Tyre pressure is one of the most important parameters to ensure road safety. Regardless of whether we are drivers of a passenger car or truck, it is a decisive factor when it comes to car’s adhesion to the road during acceleration, braking and cornering. Too low pressure means a much longer braking distance, but also a deterioration of the car’s drivability, faster tyre wear and more frequent refuelling. Without an appropriate level of this parameter, there is no safe driving – unfortunately, as many as 58% of drivers control their tyre pressure too rarely1.
Drivers should check tyre pressures at least once a month, on cold tyres or after driving no more than 2 km. This should be kept in mind especially during autumn and winter, when the low air temperature significantly reduces the pressure level in the tyre. The drop in temperatures causes the tyre pressure to decrease by 0.2 bar at 0°C, 0,3 bar at -10°C and 0,4 bar at - 20°C! Inappropriate level of this parameter also significantly impairs driveability – it is worth considering especially in autumn and winter, when conditions on the roads can be quite a challenge even for the best drivers.
Why is it so important? Only at the optimal level of pressure set by the manufacturer of a given car will the tyre – under the vehicle’s mass – adhere to the road with the largest surface area. If there is too little air in the tyre, only the shoulder blocks – not the centre of the wheel – ensure contact with the road. If the pressure is too high, the tyre also doesn’t come in contact with the road as it should – the tyre adheres to it only with the centre of the tread. To exploit the full potential of a given tyre, it is crucial that it comes to contact with the road with the full range of tyre tread width.
Excessive overheating of the inner tyre sidewall layers occurs when driving with too low tyre pressure. Longer journeys in such conditions cause irreversible destruction of the carcass and belt. In the worst-case scenario, the tyre may break while driving.
Inappropriate pressure also means faster tyre wear and more frequent refuelling due to increased rolling resistance. Therefore, negligence in this respect has not only safety implications, but will also affect the wallets of drivers and entire fleets.
The drivers of trucks should also take care of correct tyre pressure – the size of the transport fleet used in Poland is estimated at over 600,000 vehicles. For each vehicle, tyres are the only point of contact with the road and are responsible for the transmission of power and traction, which is why their quality and technical condition affect the road safety and the efficiency of business operations. Appropriate tyre pressure means better safety of drivers, longer tyre life and lower fuel consumption. In addition, caring for good technical condition of the tyres ensures greater supply dependability – improper exploitation may increase the risk of malfunction by as much as 60%!
How to control tyre pressure?
Checking doesn’t mean looking – drivers should measure the pressure using a manometer, on „cold tyres”. Simply by looking at tyres we will not be able to assess pressure drop by up to 30% and that is close to 1 bar.
There isn’t one optimal pressure value for all tyres in all vehicles. The tyre pressure value recommended by the car manufacturer can be found in the car manual and on a label inside the car (most often at the bottom of the middle pillar). This value should be the same for two tyres on one axis, because the difference can lead to „pulling” the vehicle to sides or have effect on uneven braking and reduce functioning of safety systems.
– Correct amount of air in tyres significantly reduces the risk of early tyre wear or tyre burst, but also shortens the braking distance and reduces fuel consumption. We appeal to all drivers – do not forget to measure tyre pressure. Such control, at least once a month, should be a habit – says Piotr Sarnecki, general director of the Polish Tyre Industry Association.
Tyres with the correct pressure and the proper tread height are, along with speed adjusted to prevailing conditions, a very important factor reducing the risk of aquaplaning – a phenomenon resulting from the formation of a water wedge between the tyre and the roadway, on which the car begins to slide and rapidly lose grip.
– Tyres are the second, and in cars with turbocharging the third fastest-rotating element of the car. Security systems and sensors get all information from the tyre, which makes their grip absolutely crucial to our safety – adds Piotr Sarnecki.
Correct pressure – quiet driving
Noise is a natural phenomenon that will always occur – correct tyre pressure is, however, an important noise reducing factor that can improve the driving comfort of drivers. Tyres under-inflated by 0.5 bar are 3 dB louder. This is a lot considering the fact that noise does not increase linearly with the increase in the decibel intensity. Change in the noise value by only 1 decibel actually means a 26% noise increase in comparison to the lower value.
1 Moto Data 2017 – Panel of car users