Good tires for a ETC with Z-rated option?

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Suspension, Brakes and Tires Discussion, Good tires for a ETC with Z-rated option? in Item Specific Cadillac Discussion; Hey, the tires on my ETC are almost bald, and I think I need new ones lol. I have the ...
  1. #1
    chris203's Avatar
    chris203 is offline Cadillac Owners Fanatic
    Automobile(s): 1999 Eldorado ETC-sold for 2006 GTO
    Join Date
    Nov 2003
    SF Bay Area

    Good tires for a ETC with Z-rated option?

    Hey, the tires on my ETC are almost bald, and I think I need new ones lol. I have the Z-rated tire option on my car and I was wondering what kind of tires you guys recommend and if its really necessary to have Z rated. Could I get an H or V rated tire instead? Thanks in advance!

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  3. #2
    PDBDeville is offline Cadillac Owners Member
    Join Date
    Nov 2003

    Re: Good tires for a ETC with Z-rated option?

    Here is some info to help you make your decision as it relates to speed rating:

    Beginning in 1991, the speed symbol denoting a fixed maximum speed capability of new tires must be shown only in the speed rating portion of the tire's service description, such as 225/50R16 89S. The most common tire speed rating symbols, maximum speeds and typical applications are shown below:

    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

    As vehicles have increased their top speeds into Autobahn-only ranges, the tire speed ratings have evolved to better identify the tires capability, allowing drivers to match the speed of their tires with the top speed of their vehicle.

    I recently had Falken Ziex 512's put on my Deville (235/55R16)....absolutely love them.

    Here's a link describing them:

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