How to Read Tyre Sidewall Markings — A Simple Plain-English Guide

Q: Breaking Down a Typical Tyre Size: 205/55 R16 91V

205 — The tyre width in millimetres, measured from sidewall to sidewall. A wider tyre provides a larger contact patch and generally better grip, but may affect fuel economy. 55 — The aspect ratio: the sidewall height as a percentage of the width. So a 55 profile means the sidewall is 55% of 205mm =

Those numbers and letters on the side of your tyre contain everything you need to know about it. Here's how to decode them without needing an engineering degree.

Breaking Down a Typical Tyre Size: 205/55 R16 91V

205 — The tyre width in millimetres, measured from sidewall to sidewall. A wider tyre provides a larger contact patch and generally better grip, but may affect fuel economy. 55 — The aspect ratio: the sidewall height as a percentage of the width. So a 55 profile means the sidewall is 55% of 205mm = 112.75mm high. Lower profile numbers mean a sportier, lower-profile look but less cushioning over bumps — relevant for Leeds pothole-ridden roads.

The Rest of the Code

R — Radial construction (the industry standard for all modern passenger tyres). 16 — The diameter of the wheel rim in inches that this tyre fits. This must match your wheels exactly. 91 — The load index. Each number corresponds to a maximum weight the tyre can safely carry. 91 = 615kg per tyre. V — The speed rating. V means the tyre is rated for sustained speeds up to 240km/h (149mph). Always ensure your replacement tyres match or exceed the original speed rating for your vehicle.

Other Markings You'll See

XL (Extra Load) means the tyre can carry more weight than standard — important for vans, SUVs, and heavily loaded vehicles. RFT or ROF means Run Flat Tyre. M+S (Mud and Snow) indicates some winter capability. The 3PMSF snowflake symbol indicates a tyre that genuinely meets winter performance standards. The EU tyre label shows ratings for wet grip, fuel efficiency, and noise — look for A-rated wet grip when buying in the UK.

Not Sure What Tyres You Need?

Tell us your vehicle registration when you call Leeds Tyre Guys on 0113 234 5678 and we'll identify the correct tyre size and specification immediately.