📖How to Read Your Tyre Sidewall: A Plain-English Guide
27 May 2026
Understanding 205/55 R16 91V
Every tyre carries a code on its sidewall. Here is what each number means in plain English.
205 — Width in Millimetres
The width of the tyre from sidewall to sidewall. A wider tyre gives more road contact and grip; narrower tyres have lower rolling resistance.
55 — Aspect Ratio
The sidewall height as a percentage of the width. 55 means the sidewall is 55% of 205mm = 112.75mm tall. Lower numbers (35, 40) mean sportier handling; higher numbers (65, 70) mean a softer, more comfortable ride.
R — Radial Construction
R means radial — the standard construction for all modern car tyres. ZR indicates a high-performance radial rated above 240 km/h.
16 — Rim Diameter in Inches
The wheel rim size the tyre fits. This must match exactly. A 16-inch tyre will not fit a 17-inch rim.
91 — Load Index
The maximum weight each tyre can support. 91 = 615 kg per tyre. Always match or exceed your vehicle's original load rating.
V — Speed Rating
Maximum sustained speed: T=190 km/h, H=210 km/h, V=240 km/h, W=270 km/h, Y=300 km/h. Never fit a tyre with a lower speed rating than your vehicle requires.
Finding Your Correct Size
Check your existing tyre sidewall, vehicle handbook, or the sticker inside the driver's door. Or call FixMyTyreNow on 07895 859505 with your registration plate — we'll look it up for you.
