See also:

DOT Quality Grades
Treadwear Traction AA A B C Temperature A B C Conform to Federal Safety Requirements All passenger car tires must conform to Federal Safety Requirements in addition to these grades.◀ ...

Adjusting
Vehicle Equipment ...

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 ...