Performance Tire Ratings

255/45ZR17 - Goodyear GS-CSpeed ratings are certified maximum sustained speed designations assigned to passenger car radials and high performance tires. Because of the evolution of high-speed passenger car travel in some areas of the world, it has become necessary to establish a way to rate a tire's high-speed capability. 

In the U.S., these ratings are based on tire testing in laboratory conditions under simulated loads. European testing uses actual road testing. 

245/45ZR/17 - Kumho ECSTA Supra 712For a tire to be speed rated by the U.S. Government, it must meet certain minimum government standards for reaching and sustaining that specified speed. Domestically, high performance tires must be speed rated. The tire industry defines high performance tires as those with speed symbols of "S" or greater and aspect ratios of 70 or lower. Yokohama goes one step further and defines high performance tires with a speed symbol of "H, V, W, Y," or "Z" and an aspect ratio of 70 or less (typically, 60 or less).

Conventional passenger car radials use in the U.S. need only meet the minimum Department of Transportation standard of 85 mph. and are not speed rated. On the other hand, in Europe, the tire's rating must be greater than the max speed of the vehicle.

The actual numbers below may vary by Manufacturer.
This chart is intended to be ONLY a guide.
Please consult the tire manufacturer for their current specifications!

RATING

 km/h mph

G

 90 56

J

 100 62

K

 110 68

L

 120 75

M

 130 81

N

 140 87

P

 150 93

Q

 160 99

R

 170 106

S

 180 112

T

 190 118

U

 200 124

H

 210 130

V

 240 149

W

 270 168

Y

 300 186

ZR

 over 300 over 186

When ZR appears in the tire size designation, (235 - 45ZR17) it signifies a maximum speed capability in excess of 149 mph. If a service description also appears, the maximum speed is indicated by the service description.

EXAMPLE:
 235/45ZR17 - 149+ mph
235/45ZR17 99W - 168 mph
235/45ZR17 99Y - 186 mph

Do not mix and match tires with different speed ratings on your vehicle. This can cause serious problems with the handling of your vehicle. If you desire better cornering response, there is no problem installing a higher speed rated tire on your vehicle.

Warning:
Speed ratings apply only to the tire, not to the vehicle. Putting a speed rated tire
on any car does not mean that the car can be operated at the tire's rated speed.

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