A Complete Tyre Pressure Guide

Tyre pressure might not cross your mind often, but it’s an easy way to keep your car safe and running well. If your tyres aren’t at the right pressure, you could use more fuel, risk a blowout or wear out your tyres faster. With so much depending on your tyres, knowing the right pressure is important for both your safety and your budget.

Keep reading to learn what your tyre pressure should be, when and how to check it, and how to make sure your tyres are properly inflated. You’ll find everything you need to keep your tyres in great condition.

What Should my Tyre Pressure be?

Most passenger cars have a recommended tyre pressure between 31 and 35 PSI (2.1–2.4 BAR) when the tyres are cold. However, the exact pressure varies depending on your vehicle model, tyre size and load.

PSI (pounds per square inch) and BAR (a metric unit) are the two units used to measure tyre pressure. PSI indicates the amount of pressure exerted on each square inch inside your tyre, while BAR provides a comparable measurement in the metric system. Both units ensure you can maintain the correct tyre pressure regardless of the gauge type.

You can find your car’s recommended tyre pressure in the vehicle handbook, on the label inside the driver’s door frame, or on the fuel filler cap. Proper tyre pressure helps optimize fuel efficiency, provide safe handling, and extend tyre life.

If towing or carrying heavy loads, check the manufacturer’s guidelines for a higher laden tyre pressure. Tyres with pressure below 20 PSI are generally considered flat and significantly increase the risk of a blowout.

Enter your car registration below to find the recommended tyre pressure for your vehicle.

How to Check Your Tyre Pressure?

Using a tyre gauge is one of the quickest and easiest ways to check if your tyres are inflated correctly. Here’s how to check tyre pressure:

  • Unscrew and remove the dust cap from the tyre valve.
  • Place the tyre pressure gauge firmly onto the valve stem to get an accurate seal.
  • Apply gentle pressure to the gauge until it displays a reading.
  • Review the reading to determine if the tyre needs more air or should be deflated.
  • Repeat the process for all four tyres, as each tyre’s pressure can vary.
  • Be sure to check the pressure of your spare tyre as well, since it naturally loses air over time.

If you don’t have a tyre pressure gauge at home, you can always visit your local HiQ centre, where we’ll check your tyre pressure for you. Many fuel stations also offer an air pump service, sometimes for free.

Checking tyre pressure

When should tyre pressure be checked?

You should check your tyre pressure at least every two weeks and before long journeys or motorway driving. Tyres naturally lose around 1 PSI (0.07 BAR) per month, and driving with incorrect pressure can lead to uneven tread wear, reduced fuel efficiency and poorer handling.

It’s best to check your tyre pressure when the tyres are cold, meaning the car has been driven less than 2 miles. When tyres are warm, the air inside expands and pressure increases, which can give an inaccurate reading.

Make tyre pressure checks part of your regular vehicle maintenance routine, alongside checking your tyre tread depth and inspecting tyres for any visible damage.

Cars manufactured after 2012 are typically fitted with a Tyre Pressure Monitoring System (TPMS). This system alerts you if tyre pressure drops below the recommended level, but you should still check your tyres manually to ensure they are correctly inflated.

Understanding your Tyre Pressure Monitoring System (TPMS)

A tyre pressure monitoring system alerts the driver when at least one tyre is under-inflated. Tyre Pressure Monitoring Systems monitor tyre pressure without the need for a gauge and advise motorists by showing an illuminated symbol on the dashboard panel.

Most cars manufactured after 2012 in the UK and EU are fitted with a Tyre Pressure Monitoring System (TPMS) as standard.

You can usually tell if your car has TPMS if you:

  • Look for a warning light on the dashboard shaped like a tyre with an exclamation mark inside.
  • Check your vehicle handbook.
  • Look in your car’s settings menu for tyre pressure information.

If the warning light comes on, it means one or more tyres may need to be checked and inflated. The tyre pressure warning symbol resembles a horseshoe shape with an exclamation mark in the centre. This icon appears on modern dashboards when tyre pressure drops below recommended levels.

Book a TPMS Service with HiQ today to ensure your system is working correctly.

Why is it important to check tyre pressures?

Checking your tyres is incredibly important for three main reasons:

Tyre safety

Tyre safety

If your tyre pressure is lower than the level recommended by your vehicle manufacturer, the risk of aquaplaning, where your tyres lose grip on wet surfaces, increases. It can also reduce braking performance on dry roads, causing your car to take longer to come to a complete stop. Proper tyre pressure is essential for maintaining optimal traction and safety.

Fuel economy

Fuel economy

You’ll reduce your running costs by keeping your tyres at the correct pressure. Underinflated tyres must work a lot harder than properly inflated tyres as they’re met with an increased rolling distance, which then increases your vehicle’s fuel consumption.

Longevity

Longevity

Driving with incorrect tyre pressure can lead to tyre deterioration and weakening of the reinforcing structure, which dramatically reduces the lifespan of your tyres.

Why correctly inflated tyres are important

Maintaining the correct tyre pressure is essential for vehicle safety, fuel efficiency and tyre lifespan. Tyres that are underinflated or overinflated can affect how your car handles, increase tyre wear and reduce overall performance.

Keeping your tyres inflated to the manufacturer’s recommended pressure helps ensure better grip on the road, shorter braking distances and improved fuel economy.

What happens if tyres are underinflated?

Tyres can quickly become underinflated if they are not checked regularly. Driving with low tyre pressure causes the tyre to flex more than intended, which increases friction and heat.

Common effects of underinflated tyres include:

  • Uneven tyre wear, particularly on the outer edges of the tread
  • Reduced fuel efficiency due to increased rolling resistance
  • Poorer handling and slower steering response
  • Greater risk of tyre damage or blowouts

Underinflated tyres may also make your car feel sluggish when accelerating and can sometimes cause vibration or unusual road noise.

If your tyres are low on air, use a tyre pump or air compressor to add air gradually, checking the pressure regularly until it reaches the recommended level. For more information on flat tyres, read our dedicated guide.

What happens if tyres are overinflated?

Overinflated tyres contain too much air, which reduces the amount of tyre surface in contact with the road. This can negatively affect traction and comfort while driving.

Signs and effects of overinflated tyres include:

  • Reduced grip and longer braking distances
  • Increased sensitivity to bumps and potholes
  • Uneven tyre wear in the centre of the tread
  • Reduced tyre lifespan

In some situations, such as carrying heavy loads, manufacturers may recommend slightly higher tyre pressure. Always check your vehicle handbook for the correct laden tyre pressure.

Correctly inflated

Correctly inflated tyre

Under inflated

An under inflated tyre

Over inflated

An over inflated tyre

Tyre pressure monitoring system

What should I do if my tyre pressure is too high or too low?

If your tyre pressure is too high, carefully release a small amount of air from the valve until the pressure matches the recommended PSI.

If your tyres are underinflated and you’re not near an air pump, drive cautiously and head to the nearest petrol station or garage as soon as possible. Avoid high speeds and long journeys until the tyres are inflated correctly.

A rapid loss of air in a tyre could signal a puncture or damage, and it’s important to have the tyre inspected by a professional and repaired. HiQ offers free puncture repairs to get you back on the road quickly and safely.

We get it. MOTs and car services are not the type of calendar events you look forward to. But if you look after your car, it’ll look after you. At HiQ, whether it’s a minor service or a major one, we’re all about doing things properly. And as we’re local, you can save on time and fuel miles. Keep your wheels in top condition with HiQ’s expert tyre services.