Published 2026-05-07 · TT Mobile Tyre Fitting 24/7
The numbers and letters moulded into the side of your tyre contain all the information you need to find the correct replacement. Here is how to decode them.
A typical tyre marking looks like this: 205/55 R16 91V. Each part tells you something specific.
The first number — 205 in this example — is the tyre width in millimetres, measured across the widest point of the tyre.
The second number — 55 — is the aspect ratio, which is the height of the tyre sidewall expressed as a percentage of the tyre width. A 55-profile tyre has a sidewall height equal to 55% of its width. Lower-profile tyres (35, 40, 45) have shorter, stiffer sidewalls and are associated with sportier handling and a firmer ride. Higher-profile tyres (65, 70, 80) have taller sidewalls and a more comfortable, compliant ride.
The letter R stands for Radial construction — the standard construction for all modern car tyres.
The next number — 16 — is the rim diameter in inches, meaning this tyre fits a 16-inch wheel.
The number after the space — 91 — is the load index. This is a code indicating the maximum load the tyre can carry when correctly inflated. 91 corresponds to 615kg per tyre. It is important to fit a tyre with a load index equal to or higher than the original specification.
The final letter — V — is the speed rating. This indicates the maximum sustained speed the tyre is designed for. Common ratings include T (190km/h), H (210km/h), V (240km/h), W (270km/h) and Y (300km/h). Always fit a tyre with a speed rating equal to or higher than the original specification.
The DOT code elsewhere on the sidewall ends in four digits indicating the week and year of manufacture — for example, 1223 means the tyre was made in the 12th week of 2023.
When you call TT Mobile Tyre Fitting 24/7 on 07762 455291, just read us the full marking from your tyre and we will find the right replacement. We cover all of Birmingham and the West Midlands, 24 hours a day.