How to read tyre codes UK - what do the numbers mean?

Tyre codes are alphanumeric markings on your tyre's sidewall that indicate key specifications like width, aspect ratio, and speed rating. In the UK, common tyre codes like '205/55 R16 91V' break down as: 205mm width, 55% aspect ratio, 16-inch rim diameter, 91 load index (615kg), and V speed rating (149mph). Popular UK models like the Vauxhall Corsa typically use 195/65 R15 tyres, while a BMW 3 Series might require 225/45 R18 tyres. These codes ensure you get the correct tyres for your vehicle's safety, performance and fuel efficiency. The markings also show compliance with EU/UK regulations (marked by an 'E' or 'e' code) and may include the 'M+S' (mud and snow) designation for all-season tyres.