Speed Rated Tires
Thread Starter
Instructor
Joined: Jan 2011
Posts: 103
Likes: 4
From: Wrentham MA
Speed Rated Tires
Am shopping around for tires, and found that many of the tires listed at NTB and TownFairTire for the C5 are not Z rated, which I thought the stock tires were. (I also looked at TireRack, but don't recall noticing speed ratings) Instead, I'm seeing W and Y rated tires. Is this any issue?
I realize that the Z rated is for 149+, and I'll never approach those speeds, heck it is a push for me to hit 74 (with the speed of traffic of course).
Any issue with going with a W or Y rated tire compared to a Z rated?
Search was not helpful to me in this case.
I realize that the Z rated is for 149+, and I'll never approach those speeds, heck it is a push for me to hit 74 (with the speed of traffic of course).
Any issue with going with a W or Y rated tire compared to a Z rated?
Search was not helpful to me in this case.
Melting Slicks
Joined: Jul 2004
Posts: 3,092
Likes: 120
From: orlando florida
St. Jude Donor '15
http://www.tirerack.com/tires/tirete....jsp?techid=35
Some tires are what's called limited z rating. You will be fine.
Some tires are what's called limited z rating. You will be fine.
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.
W168 mph270 km/hExotic Sports CarsY186 mph300 km/hExotic 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.
225/50ZR16in excess of 149 mph, 240 km/h205/45ZR17 88W168 mph, 270 km/h285/35ZR19 99Y186 mph, 300 km/h
Most recently, when the Y-speed rating indicated in a service description is enclosed in parentheses, 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 99Y186 mph, 300 km/h285/35ZR19 (99Y)in excess of 186 mph, 300 km/h
As vehicles have increased their top speeds into Autobahn-only ranges, the tire speed ratings have evolved to better identify the tire's capability, allowing drivers to match the speed of their tires with the top speed of their vehicle.
W168 mph270 km/hExotic Sports CarsY186 mph300 km/hExotic 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.
225/50ZR16in excess of 149 mph, 240 km/h205/45ZR17 88W168 mph, 270 km/h285/35ZR19 99Y186 mph, 300 km/h
Most recently, when the Y-speed rating indicated in a service description is enclosed in parentheses, 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 99Y186 mph, 300 km/h285/35ZR19 (99Y)in excess of 186 mph, 300 km/h
As vehicles have increased their top speeds into Autobahn-only ranges, the tire speed ratings have evolved to better identify the tire's capability, allowing drivers to match the speed of their tires with the top speed of their vehicle.
Last edited by mrr23; May 14, 2015 at 08:20 AM.
Thread Starter
Instructor
Joined: Jan 2011
Posts: 103
Likes: 4
From: Wrentham MA
http://www.tirerack.com/tires/tirete....jsp?techid=35
Some tires are what's called limited z rating. You will be fine.
Some tires are what's called limited z rating. You will be fine.
Thanks!
