tire speed rating?

[ericismyname]

i was lookin at tires and alot of them have a letter and a speed rating i was wondering if someone could tell me which one is the best

 

[TSiAWD666]

Go to www.tirerack.com (or try google, it's amazing how it helps you find info) and you can read up on what sidewall markings for tires mean. I'm sure you'll find it with a bit of searching.

Short answer you should not worry so much about the speed rating unless you plan on going higher than the rating for the tire you're interested in.

 

[Defiant]

Pasted from Tire Rack:

N 87 mph 140 km/h Temporary Spare Tires
P 93 mph 150 km/h
Q 99 mph 160 km/h Studless & Studdable Winter Tires
R 106 mph 170 km/h H.D. Light Truck Tires
S 112 mph 180 km/h Family Sedans & Vans
T 118 mph 190 km/h Family Sedans & Vans
U 124 mph 200 km/h
H 130 mph 210 km/h Sport Sedans & Coupes
V 149 mph 240 km/h Sport Sedans, Coupes & Sports Cars

When Z-speed rated tires were first introduced, they were thought to reflect the highest tire speed rating that would ever be required, in excess of 240 km/h or 149 mph. While Z-speed rated tires are capable of speeds in excess of 149 mph, how far above 149 mph was not identified. That ultimately caused the automotive industry to add W- and Y-speed ratings to identify the tires that meet the needs of new vehicles that have extremely high top-speed capabilities.

W 168 mph 270 km/h Exotic Sports Cars
Y 186 mph 300 km/h Exotic Sports Cars

While a Z-speed rating still often appears in the tire size designation of these tires, such as 225/50ZR16 91W, the Z in the size signifies a maximum speed capability in excess of 149 mph, 240 km/h; the W in the service description indicates the tire’s 168 mph, 270 km/h maximum speed.

225/50ZR16 in excess of 149 mph, 240 km/h
205/45ZR17 88W 168 mph, 270 km/h
285/35ZR19 99Y 186 mph, 300 km/h

Most recently, when the Y-speed rating indicated in a service description is enclosed in parenthesis, such as 285/35ZR19 (99Y), the top speed of the tire has been tested in excess of 186 mph, 300 km/h indicated by the service description as shown below:

285/35ZR19 99Y 186 mph, 300 km/h
285/35ZR19 (99Y) in excess of 186 mph, 300 km/h

 

[Zex4g63]

On a side note. The Goodyear rep told me it was not the maximum speed you could go but the maximum continuous speed you could go. He said tires with lower speed ratings could withstand higher speeds for short periods of time. I'll take his word for it because I'm not going to test that theory.

 

[ericismyname]

thanks!

 

[DeezNutsForYou]

From what I understand their specific indicates the highest speed that they can spin before they start to loose their shape and stretch. They only stretch up and down, like a dragsters tires. I'm sure everyone has seen top fueler lite up his tires and they grow like 4 inches taller. But I don't know for sure, this is just what I've heard, but it makes sense.