Tyres are the most safety-critical component on your car, yet they are often the most neglected. They are the only part of your vehicle that actually touches the road, and their condition directly affects your braking distance, handling, fuel consumption, and comfort.
This guide covers everything you need to know about car tyres — from reading the markings on the sidewall to knowing when it is time for a replacement.
How Do You Read Tyre Markings and Sizes?
Every tyre has a series of numbers and letters printed on the sidewall. For example: 205/55 R16 91V. Here is what each part means:
- 205 — The tyre’s width in millimetres
- 55 — The aspect ratio (sidewall height as a percentage of the width)
- R — Radial construction (virtually all modern car tyres)
- 16 — The wheel diameter in inches
- 91 — The load index (maximum weight the tyre can support)
- V — The speed rating (maximum safe speed for the tyre)
You must always replace tyres with the same size and at least the same load and speed rating as originally fitted. This information is also on a sticker inside the driver’s door frame.
What Are the Different Types of Car Tyres?
Summer Tyres
Designed for warm, dry, and wet conditions above 7°C. They use a harder rubber compound that provides excellent grip and low rolling resistance in warm temperatures but becomes rigid and loses grip in cold weather.
Winter Tyres
Built with a softer rubber compound that stays flexible below 7°C. They also feature deeper tread patterns designed to clear snow and water more effectively. In cold conditions, winter tyres can reduce braking distances by up to 30% compared to summer tyres.
All-Season Tyres
A compromise between summer and winter tyres that provides acceptable performance year-round. They are increasingly popular in the UK, where winters are generally mild but occasionally cold. All-season tyres are a practical choice for drivers who do not want to swap tyres twice a year.
Run-Flat Tyres
These tyres can continue to be driven for a limited distance (typically 50 miles at up to 50 mph) after a puncture. They are fitted as standard on many BMW, Mercedes, and MINI models. The trade-off is a slightly firmer ride and higher replacement cost.
When Should You Replace Your Car Tyres?
Tread Depth
The legal minimum tread depth in the UK is 1.6mm across the central three-quarters of the tyre around its entire circumference. However, tyre performance begins to degrade well before this point. Most safety organisations recommend replacing tyres at 3mm, particularly for wet weather driving.
You can check your tread depth using a tread depth gauge (available for a couple of pounds) or the 20p coin test. Insert a 20p coin into the main tread groove — if you can see the outer band of the coin, your tread is below 3mm and replacement should be planned.
Age
Even tyres with plenty of tread should be replaced after 5–6 years. Rubber degrades over time through a process called oxidation, which causes cracking and loss of flexibility. You can find the manufacturing date on the tyre sidewall — look for a four-digit number in an oval. For example, “2223” means the tyre was made in week 22 of 2023.
Damage
Inspect your tyres regularly for:
- Bulges or blisters on the sidewall (internal structural damage — replace immediately)
- Cuts or gashes deeper than 1mm
- Objects embedded in the tread (nails, screws, glass)
- Uneven wear patterns (indicating alignment or suspension issues)
Why Does Tyre Pressure Matter for Safety and Fuel Economy?
Maintaining the correct tyre pressure is one of the simplest and most impactful things you can do for your car.
Underinflated tyres increase fuel consumption, wear out faster on the edges, generate more heat (increasing blowout risk), and reduce handling precision.
Overinflated tyres wear out faster in the centre of the tread, reduce the contact patch with the road (reducing grip), and cause a harsher ride.
Check your tyre pressures at least once a month using a reliable gauge. The correct pressures for your car are listed in the owner’s manual and on a sticker in the driver’s door frame. Remember to check them when the tyres are cold — pressures increase as tyres warm up from driving.
How Often Should You Rotate Your Car Tyres?
Rotating tyres between positions on your car helps them wear evenly and last longer. Front tyres typically wear faster than rears because they handle both steering and most of the braking force.
A common rotation pattern is to move the fronts to the rear and the rears to the front, switching sides as you go. Aim to rotate your tyres every 8,000–10,000 miles or at every service.
How Can You Save Money on Car Tyres?
- Buy in pairs: Always replace tyres in pairs (both fronts or both rears) to maintain balanced handling. Fitting a single new tyre alongside a worn one is a false economy.
- Compare prices: Online tyre retailers often undercut traditional garages by 20–30% and can arrange fitting at a local partner.
- Maintain correct pressures: Properly inflated tyres last significantly longer.
- Fix alignment issues promptly: Misaligned wheels cause rapid uneven wear that can ruin a tyre in a few thousand miles.
How Can You Track Tyre Maintenance with an App?
Keeping track of when you last replaced or rotated your tyres can be difficult to remember months or years later. Cars Guru lets you log tyre changes, record costs, and set reminders for your next rotation or replacement. Combined with the app’s comprehensive maintenance tracking and OBD2 diagnostics, you have everything you need to keep your car — and its tyres — in top condition.
Download Cars Guru today and never lose track of your tyre maintenance again.