4x4 tyre markings

You may find some specific dimensions and markings on the sidewalls of 4x4 tyres.
BFGoodrich explains how to decipher these markings.

THE DIFFERENT TYPES OF SIZE MARKINGS

The metric system

255/55  R 18 : Dimension (255 = Largeur boudin, 55 = Rapport H/S, R = Radial, 18 = Diamètre talon en pouces), 4X4 : Gamme, MACADAM : Appellation commerciale, 109 H : Indice charge/vitesse

The imperial system

7.50 R 16 : Dimension (7.50 = Largeur boudin en pouces, Rapport H/S = 100, R = Radial, 16 = Diamètre talon en pouces), C 4x4 : Gamme, O/R XZL : Appellation commerciale, 104 Q : Indice charge/vitesse

The flotation system

31 X 10.50 R15 : Dimension (31 = Diamètre extérieur en pouces, 10.50 = Largeur boudin en pouces, R = Radial, 15 = Diamètre talon en pouces), LT/C : Catégorie, All Terrain T/A KO : Appellation commerciale, 109 Q : Indice charge/vitesse

SPECIFIC MARKINGS

  • T/A: Traction Avantage
  • KO: Key benefit for mixed use
  • KM: Key benefit for mud
  • M+S: MUD and SNOW: found on most 4x4 tyres. Indicates that the tyre is suited to driving in mud and snow
  • P: PASSENGER: US marking indicating that the tyre is suited to touring vehicles
  • LT: LIGHT TRUCK: US marking indicating that the tyre is suited to light trucks
  • REINF/Reinforced: Indicates that the load index exceeds the standard version
  • XL/ExtraLoad: Same meaning as REINF and Reinforced