Allied Advice: How do Tyre Pressure Sensors Work?

There’s a lot of information out there about ideal tyre pressures and how to avoid running flat. We’ve done our research and put together some helpful information to prevent low pressure. A few things to note first are:

  • Tyre pressures are normally higher in your front tyres than in your rear tyres. This is to compensate for the extra weight in the front of the vehicle from the engine.
  • Tyre pressures can reduce in cold weather. Your tyre’s pressure will drop around 1 psi for every 5.5°C drop in air temperature, your warning light may come on in this instance, however, after driving for a few miles your tyre should heat up and it should go off. Always get your car checked out at a repair centre if warning lights persist or are red.

What are tyre pressure monitoring systems?

There are two main common types of tyre pressure monitoring systems or TPMS:

  • Direct, which uses sensors attached inside the tyre that monitor the pressure levels. When the pressure decreases to a specified level, the sensor notifies the car’s ECU which then illuminates the dashboard light. Direct TPMS gives consistent accurate readings for all wheels.
  • Indirect, which uses a cars ABS wheel speed sensors to identify wheels that are turning at different speeds. Underinflated tyres have a smaller rolling radius, therefore turn at a different speed to the others, the sensors then detect that. This system is much simpler than direct, however, less accurate and prone to more false alarms. The system also cannot detect if all four tyres are low.

Why is tyre pressure important?

An under-inflated tyre is less safe. Braking distances can be cut short and produce inconsistent handling for the driver in the event of emergency braking or swerving. Your fuel consumption also increases with low tyre pressure as there is extra drag on the tyre which in turn increases the emissions of your car. Having the correct tyre pressure is also extremely important because your tyre can actually heat up and wear down quicker than a correctly inflated one, this could cause your tyre to fail and have disastrous consequences!

How to check your car’s tyre pressure

The machines at petrol stations are ideal for checking your tyre pressure and probably the easiest option for you. You can, however, also use a foot pump or a tyre pressure gauge as the principles stay the same;

  • Remove the valve cap (you’ll find this near the rim of the wheel)
  • Push the gauge onto the valve and it’ll give you a reading
  • If the air keeps coming out, push a little harder!

There’s never a good time for a flat tyre if you experience one, our Glasgow and Edinburgh service & repair centres are here to help. With competitive prices and helpful staff, why not give us a call?