WHAT IS TIRE SPEED RATING?

TIRE SPEED RATINGS, EXPLAINED

A SIMPLE EXPLANATION OF TIRE SPEED RATING

WHAT IS TIRE SPEED RATING?

A tire’s speed rating indicates the optimal speed that the tire can safely maintain over time. In short, it’s the fastest speed a tire can handle before it no longer performs as designed. The higher the speed rating, the better control and handling you’ll have at higher speeds.

The speed rating system was developed to help control the safe performance of tires at standardized speeds. A tire’s certified speed rating is given a letter from A to Z, ranging from 5km/h (3mph) to above 300 km/h (186 mph).

This rating system (see below) shows the top speed for which a tire is certified. It does not indicate the total performance capability of a tire.

WHY WERE TIRE SPEED RATINGS DEVELOPED?

The speed rating system used today was developed in Europe in response to the need to control the safe performance of tires at standardized speeds. When the rating system was originally developed, the “Unlimited V” category of over 210 km/h (130 mph) was the top speed rating possible.

As manufacturers developed bigger and better tires, it became necessary to regulate performance at standardized speeds to ensure safety. The “Limited V” category of 250 km/h (149 mph) was then created, and eventually the “Z” speed rating was added as the top speed rating. (Always consult the manufacturer for the maximum speed of Unlimited Z tires.)

WHERE CAN I FIND MY TIRE SPEED RATING?

You can find your tire speed rating in a number of places, typically in the owner’s manual, driver’s side doorjamb, glove box door, and gas tank hatch. Recent standardization has changed so all ratings except “Unlimited ZR” incorporate the speed symbol and load index as part of every tire’s service description on the tire’s sidewall. If you’re reading your tire sidewall, the speed rating will be the last item in the character sequence in the tire’s size code. Below is an example of a the description on a tire’s sidewall: 2015/60R15 91V. Here, the tire would have a speed rating of V. V-rated tires can be driven at 149 MPH.

TIRE DESCRIPTION

205/60R15 91V
205 = Section Width in Millimeters
60 = Aspect Ration
R = Radial Construction
15 = Rim diameter in Inches
91 = Load IndexService Description
V = Speed Symbol

ZR DESIGNATION

Tires having a maximum speed capability over 149 MPH may have “ZR” in the size designation. Tires with a maximum speed capability over 186 MPH are required to include “ZR” in the designation. Below are examples of tire sizes with a “ZR” speed rating.

ZR DESIGNATION

EXAMPLES
Tire DesignationMaximum Speed
P275/40ZR17 93W270 km/h (168 mph)
P275/40ZR17 93Y300 km/h (186 mph)

TIRE SPEED RATING CHART

For tires with a maximum speed capability higher than 240 km/h (149 mph), a “ZR” may appear in the size designation. Tires with a maximum speed capability higher than 300 km/h (186 mph), require a “ZR” in the size designation. Consult the tire manufacturer for maximum speed when there is no service description.

TIRE SPEED CAPABILITIES

SPEED SYMBOLS
Symbol SpeedSpeed (km/h)Speed (mph)
A153
A2106
A3159
A42012
A52516
A63019
A84025
B5031
C6037
D6540
E7043
F8050
G9056
J10062
K11068
L12075
M13081
N14087
P15094
Q160100
R170106
S180112
T190118
U200124
H210130
V240149
W270168
Y300186

TURN TO TIRES PLUS FOR HELP

Need help understanding the speed rating on tires? Our technicians have got you covered. Bring your vehicle by your local Tires Plus and we’ll help you understand your tire numbers, tire size, and more! 

Source: https://www.tiresplus.com/tires/tire-buying-guide/tire-speed-rating/

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