See also:

Tire size
Example: 255/55 R 19 107 V 255: nominal width in mm 55: aspect ratio in % R: radial tire code 19: rim diameter in inches 107: load rating, not for ZR tires V: speed rating, before the R on ZR ti ...

External devices
At a glance ...

Tire identification marks
Tire size 255/50 R 19 103 Y 255: nominal width in mm 50: aspect ratio in % R: radial tire code 19: rim diameter in inches 103: load rating, not for ZR tires Y: speed rating, before the R on ZR ...