The numbers and letters on the tyre wall show the tyre size and more information. It's not difficult to understand their meaning.

Example : 195/60 R 15 V

195 = Section width in mm
60 = Ratio of sidewall height to section width
R = Radial construction
15 = Wheel diameter in inches
V = Speed rating index (see below)
Speed rating indexes and the corresponding maximum speed
Q = 160km/h S = 180km/h T=190km/h
U = 200km/h H = 210 km/h V = 240 km/h
W = 270 km/h Z = above 270 km/h