Good tires for a ETC with Z-rated option?

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Results 1 to 2 of 2
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!

  2. Remove Advertisements

  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:

  4. Remove Advertisements
    Cadillac Forums

+ Reply to Thread

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

What Cadillac(s) do you own? (Or type NONE)

Please select your insurance company (Optional)

Your date of birth and age are displayed in several places on the forum. Only the administrator will have access to your date of birth should you choose to hide it via the privacy option below.


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts