How to Choose the Right Tyre Size for Your Car
Buying Guide4 min read28 January 2026

How to Choose the Right Tyre Size for Your Car

How to Choose the Right Tyre Size for Your Car

Fitting the wrong tyre size can affect handling, fuel economy and even your MOT. Here is how to get it right every time.

The simplest way to find the correct tyre size for your vehicle is to check the tyre placard — a sticker located inside the driver's door jamb, in the glove box or in the fuel filler flap. This sticker lists the exact tyre sizes approved for your vehicle by the manufacturer, along with the recommended inflation pressures. Alternatively, you can find the size on the sidewall of your current tyres.

It is possible to fit alternative tyre sizes within a small approved range without affecting vehicle safety, but any deviation from the manufacturer's specified size should be checked carefully. Fitting a tyre with a different overall diameter will affect your speedometer reading, potentially making it inaccurate by enough to cause legal and safety issues. Wider tyres may also rub on the wheel arch under load or full steering lock.

When in doubt, provide your vehicle registration number when ordering tyres and our team will cross-reference the correct size for your exact make, model and year. Royal Mobile Tyres Cardiff stocks thousands of tyre sizes and can confirm availability and pricing before we arrive. Getting the right size the first time avoids delays and ensures your tyre performs exactly as intended.

#tyre size#tyre guide Cardiff#correct tyre#buying guide

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