Motorized vehicle tires all have speed ratings, which fall into one of the following categories:
  • Q = 99 MPH, 160km/h
  • S = 112 MPH, 180km/h
  • T = 118 MPH, 190km/h
  • U = 124 MPH, 200km/h
  • H = 130 MPH, 210km/h
  • V = 149 MPH, 240km/h
  • W = 168 MPH, 270km/h
  • Y = 186 MPH, 300km/h
  • Z = 149 MPH, 240km/h or higher

Obviously, there are other categories for racing, but I'm only covering consumer level tires here.

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