Regularly checking your tyre pressure and tread depth is one of the simplest yet most important maintenance tasks you can perform. This guide shows you exactly how to do both correctly.
Why These Checks Matter
Correct tyre pressure and adequate tread depth are essential for safety, fuel efficiency, and tyre longevity. Under-inflated tyres can increase fuel consumption by up to 3%, while insufficient tread depth dramatically increases stopping distances in wet conditions. Regular checks take just minutes but can prevent accidents and save money.
Checking Tyre Pressure: Step-by-Step
What You'll Need
- Tyre pressure gauge (digital or analog)
- Air compressor or access to a petrol station air pump
- Your vehicle's recommended pressure specifications
Step 1: Find the Correct Pressure
Your vehicle's recommended tyre pressure is found in three places:
- A sticker on the driver's door frame or door edge
- Inside the fuel filler cap
- In your vehicle's owner's manual
Note that front and rear tyres may require different pressures, and the pressure may vary depending on load. The pressure is measured in PSI (pounds per square inch) or BAR.
Important Tip
Always check tyre pressure when tyres are cold (before driving or after the car has been parked for at least 3 hours). Driving heats up tyres and increases pressure, giving inaccurate readings.
Step 2: Remove the Valve Cap
Unscrew the valve cap from the tyre valve stem and keep it in a safe place. The valve stem is usually located on the inner side of the wheel.
Step 3: Take the Reading
Press the tyre pressure gauge firmly onto the valve stem. You'll hear a brief hiss of air - this is normal. The gauge will display the current pressure. For digital gauges, wait for the reading to stabilize. For analog gauges, read the measurement where the stick extends from the gauge.
Step 4: Adjust if Necessary
If the pressure is too low, add air using a compressor or petrol station pump. Check the pressure frequently while adding air to avoid over-inflation. If the pressure is too high, press the small pin in the center of the valve stem to release air in short bursts, checking pressure between releases.
Step 5: Replace the Valve Cap
Once the pressure is correct, replace the valve cap securely. The cap prevents dirt and moisture from entering the valve, which could cause air leaks.
Step 6: Repeat for All Tyres
Check all four tyres, including the spare if your vehicle has one. Don't forget that front and rear tyres may require different pressures.
Checking Tread Depth: Step-by-Step
Method 1: The 20p Test
The simplest method requires only a 20p coin:
- Take a 20p coin and insert it into the main tread grooves of your tyre
- If the outer band of the coin is visible, your tread is below the legal limit of 1.6mm
- Check multiple points across the tyre, as wear can be uneven
- Test all four tyres in several places
Legal Requirement
The legal minimum tread depth in the UK is 1.6mm across the central three-quarters of the tyre, around the entire circumference. However, we recommend replacing tyres at 3mm for optimal safety.
Method 2: Using a Tread Depth Gauge
For more accurate measurement, use a tread depth gauge (available at automotive stores for under £5):
- Insert the probe of the gauge into a tread groove
- Press down until the base of the gauge is flush with the tread
- Read the measurement on the gauge
- Take measurements at multiple points across each tyre
- Record the shallowest measurement for each tyre
Method 3: Tread Wear Indicators
Modern tyres have built-in tread wear indicators (TWI):
- Look for small raised bars in the tread grooves
- These bars are exactly 1.6mm high (the legal minimum)
- When the tread is level with these bars, the tyre is at the legal limit
- Replace tyres before reaching this point for optimal safety
Understanding Uneven Wear Patterns
While checking tread depth, look for uneven wear patterns that may indicate problems:
Center Wear
Excessive wear in the center of the tread indicates over-inflation. Reduce tyre pressure to the recommended level.
Edge Wear
Wear on both outer edges suggests under-inflation. Increase tyre pressure and check for leaks.
One-Side Wear
Wear on one side indicates misalignment. Have your wheel alignment checked and corrected professionally.
Patchy Wear
Irregular patches of wear suggest wheel imbalance or suspension issues. Have your vehicle inspected by a professional.
How Often Should You Check?
Establish a regular checking routine:
- Tyre Pressure: At least once a month and before long journeys
- Tread Depth: Monthly visual checks, detailed measurement every 3 months
- Visual Inspection: Weekly quick checks for obvious damage or objects in the tread
Free Tyre Checks at IQ Tyres
Not sure about your tyre condition? Visit IQ Tyres in Mitcham for a free tyre check. Our experienced technicians will check your tyre pressure, tread depth, and overall condition, providing expert advice on any issues found.
Conclusion
Checking tyre pressure and tread depth is quick, easy, and essential for safe driving. Make these checks part of your regular vehicle maintenance routine. If you notice any unusual wear patterns, damage, or if you're unsure about your tyre condition, don't hesitate to visit our team at IQ Tyres for professional advice and service.