Boosting your vehicle’s speed is possible with the right tire. The “Z” rating on tires is not a non-standard designation: It means that the tire meets or exceeds the highest performance requirements of a given vehicle.
A “Z” rating may appear in the middle of tire size and indicate either a maximum speed over 149 mph (240 kph) or 186 mph (300 kph). There are so many tire ratings out there, it can be hard to know what they mean. A tire’s “Z” rating is one of the most misused, and misunderstood terms.
If you’re wondering how much speed a tire can handle, Z-rated tires can handle up to 149 mph (240 kph). The rating is based on a tire’s maximum speed and its stopping distance in response to different braking methods.
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Are Z-rated tires necessary?
It’s not necessary to have a Z-rated tire. However, it should be noted that the Z rating on a tire is the maximum speed capability of the tire (over 149 mph). If you’re going to be driving at speeds over 120 mph, then it would certainly be wise to have a Z-rated tire.
You can find your tire’s speed rating by reading the size code on the tire’s sidewall. Typically following the load index, your tire rating is represented by a letter that directly corresponds to the tire’s max speed.
If you’re just looking for a replacement or something with a little extra bite on dry pavement, look for something with an H or V rating.
Tire speed ratings are letters assigned to tires to indicate how fast they can safely travel. The letters range from A through Z, with each letter corresponding to a different maximum speed.
For example, tires with an A rating can only travel up to 15 mph while Z-rated tires can travel over 150 mph.
The speed rating of a tire isn’t just about top speed. For example, a Z-rated tire is constructed with reinforced sidewalls and a unique internal structure to prevent the tire from overheating at high speeds.
This means that even if you’re not planning on driving 149+ mph, you’ll still benefit from the added strength of a Z-rated tire in everyday driving conditions.
Check what is X/T tire.
Check what is XL on tires.
What is the difference between ZR and R on Tires?
Thus, a ZR tire has a speed index of V, W, or Y. R indicates that the structure is RADIAL. There is therefore no difference between a ZR and an R tire with the same speed index.
The speed index of your tires should correspond to the maximum speed recommended by your vehicle’s manufacturer. In the 1980s, tire manufacturers used a marking system that is no longer used today.
The speed symbols on tires are still in use today:
- Speed symbol: L – maximum speed up to 75 mph/120 km/h;
- Speed symbol: M – maximum speed up to 81 mph/130 km/h;
- Speed symbol: N – maximum speed up to 87 mph/140 km/h;
- Speed Symbol: P – maximum speed up to 94 mph/150 km/h;
- Speed Symbol: Q – maximum speed up to 100 mph/160 km/h;
- Speed symbol: R – maximum speed up to 106 mph/170 km/h;
- Speed symbol: S – maximum speed up to 112 mph/180 km/h;
- Speed symbol: T – maximum speed up to 118 mph/190 km/h;
ZR tires have higher speed ratings than R tires with the same load index and size. As a reminder, there are two types of tire structures.
Radial tires. The carcass is made of fabric cords arranged at 90° to the tread. This carcass provides excellent driving comfort and better resistance to heat build-up at high speeds.
The carcass is made of fabric cords arranged at 90° an angle to the tread. These tires have less grip on wet surfaces and wear out more quickly.
What do Z and R mean in tires?
A “Z” rating can mean different things. While it nearly always means a high-performance tire for high-performing sports cars, “Z” may appear in the middle of a tire’s size information. When it does, it represents either a maximum speed of more than 149 mph (240 kph) or 186 mph (300 kph).
By contrast, an “R” rating indicates that the tire is good for up to 149 mph (240 kph) — anything higher requires a “Z” rating.
In the U.S.A., it was once common for cars to be fitted with R-rated tires – these are made to go up to 106 mph, which is more in keeping with our roads and speeds here, but not many of those are about now either. The Z rating means the tire is capable of exceeding 149 mph and/or 186 mph.
Z and R in tires mean the tire is radial, while the Z means it has a speed rating above 149mph, R is rated at 149mph or less.
There is nothing like an R tire, it’s simply a code for a “radial” tire. It was used when bias-ply tires were still common and only performance cars had radials. As such the terms are obsolete today.
If you’re shopping for high-speed capable tires and you see a tire with a “Z” in its size designation, be sure to check the maximum inflation pressure marked on the sidewall to determine if it’s suitable for your vehicle. If not, you’ll need to look elsewhere.
What is the ZR rating on a tire?
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:
- P225/50ZR16 91W
- P245/40ZR17 91W
- P215/45ZR17 91Y
The “Z” in the tire size designation indicates that the tires are rated “over 149 MPH.” The “ZR” indicates that the tires are rated over 186 MPH. Ex: ZR-rated tire – ZR17 (84W).
To make sure that your tires are rated for their appropriate speed, check your tire’s sidewall for a letter (or letters) after the width, height, and diameter measurements.
These letters indicate what type of vehicle will be able to use the tire (e.g., passenger car, light truck, or SUV). The speed rating is indicated by an alphabetical letter enclosed in a circle on the sidewall of your tire.
- 265/50ZR16
- 295/40ZR17
- 285/30ZR18
The speed rating is the letter at the end of the tire size. If there is no letter at the end of the tire size, then the speed rating for that tire is “T,” meaning 118 mph.
P-Metric Passenger Tires:
Example Tire Size: P225/60R16 97H
Example Tire Size: P225/60ZR16 97W
LT-Metric Light Truck Tires:
Example Tire Size: LT235/85R16 120/116Q
Example Tire Size: LT245/75ZR16 120/116Q
Flotation Sizes: For tires that have a section width of 12 inches or greater and have a load index of 105 or less, an “E” can be used in place of the “P” to indicate the tire is intended for light truck use.
However, all other rules for the construction and performance requirements for passenger tires must be met.
What do the numbers on tires mean?
The two-digit number after the slash mark in a tire size is the aspect ratio. For example, in a size P215/65 R15 tire, the 65 means that the height is equal to 65% of the tire’s width. The bigger the aspect ratio, the bigger the tire’s sidewall will be.
If you replace your OEM tires with aftermarket tires having a different aspect ratio from those that came stock on your vehicle, you may have issues with speedometer accuracy and the operation of your antilock brakes (ABS) or traction control system (TCS).
The letter following the aspect ratio represents the tire’s construction type. R stands for radial construction and B stands for bias construction. All tires sold today are radial tires, so you won’t see that letter on any new car or light truck tires.
A tire’s section width is measured in millimeters from sidewall to sidewall. This measurement changes when the tire is installed on a wheel and inflated.
The two- or three-digit number after R denotes the tire’s internal construction. “R” stands for Radial, which means that cords inside extend at a 90-degree angle from one bead to another.
What does 96/y/Z mean on a tire?
In a tire marked “245/40R19 96Y,” the “96Y” represents the tire’s load index and speed rating.
The load index indicates the maximum weight that a tire can support when properly inflated. You’ll find a load index chart in our Tire Tech Center.
The number 96 in our example corresponds to a maximum load capacity of 1,709 pounds, while a higher-numbered load index such as 130 would translate to a higher weight rating of 3,086 pounds.
The speed rating indicates the maximum speed that the tire can carry a load under specified service conditions.
A speed rating is not necessarily the top speed that the tire can be safely driven at, but rather an indication of its ability to handle sustained speeds for long periods.
The “96” at the beginning tells the tire’s load index or its maximum load-bearing capability. A 96 has a maximum load capacity of 1,150 pounds, according to the Tire Rack.
What is the maximum speed of a Z-rated tire?
Z speed-rated tires are for high-performance cars. The letter “Z” may appear in the middle of a tire’s size information.
Z is the highest (and fastest) speed rating you’ll find on most sports cars and high-performance vehicles. A Z-speed rated tire can exceed 149 mph or 240 km/h.
The “ZR” that sometimes precedes the size designation does not indicate a separate speed rating.
It simply means that the tire has a Z rating for speeds above 149 mph or 240 km/h. Tires with a Z-rating are designed to handle speeds at or above 149 mph or 240 kph.
They are also designed to handle extremely high heat caused by the high speeds at which they operate.
Even if you do not drive your car at extremely high speeds, Z-rated tires can provide you with an enhanced level of steering response and cornering grip.
Are ZR tires still relevant?
To be more precise, all these ZR tires are meant for cars that can reach at least 150mph.
Nowadays, the marking ZR is not relevant anymore but it is still used in the catalogs of manufacturers and tire retailers.
ZR tires are more expensive than non-ZR-rated ones because the materials used have a higher quality and make the tires more durable.
ZR tires include the speed ratings V (149mph), W (168mph), and Y (186mph). ZR tires are the highest-speed tires on the market.
The difference to other high-performance tires is that ZR tires have a “Z” as the first letter in their marking.
Until 1999, ZR was also used as a tire category but since 2000, all ZR tires are marked with a W, V, or Y rating and therefore they can be classed as Ultra High Performance (UHP) tires.
The change happened because of the new European standards for tire categories.
There is one important thing to know about these high-performing tires: They are mostly made with hard rubber compounds which usually result in poor wet grip and short tire life.
Nowadays, the marking ZR is not relevant anymore but it is still used in the catalogs of manufacturers and tire retailers. The main reason for this is that many customers are still using the rating to find a new set of tires.
Conclusion
In the early days of tire manufacturing, a tire’s speed rating was expressed as a letter. This was changed when the number of vehicle speeds and tire ratings grew too large to designate with the 26 letters in the English alphabet.
A “Z” rating can mean different things. While it nearly always means a high-performance tire for high-performing sports cars, “Z” may appear in the middle of a tire’s size information.
When it does, it represents either a maximum speed of more than 149 mph (240 kph) or 186 mph (300 kph).
Frequently Asked Questions
1. Do I need ZR tires?
ZR stands for Z Rated. This is a designation that the tire manufacturer gives their tires to indicate they are certified to be driven at speeds up to 149 MPH. Not all tires are Z-rated.
The speed rating is indicated on the tire sidewall with a letter code. For example, you may see HR on your tires, which means they are rated to be driven at 130 MPH.
Most vehicles will never be driven at speeds of 149 mph or higher. However, if you want to drive your vehicle at those speeds, then you should consider getting ZR tires instead of HR or VR tires.
2. Are ZR tires better than R?
ZR tires are usually found in high-end sizes, like 17-inch and up. Some sports cars will have ZR tires as stock equipment.
ZR tires are designed with more efficient hydroplaning resistance, which is why they’re considered high-speed tires.There is therefore no difference between a ZR and an R tire with the same speed index.
3. Are z rated tires repairable?
Can tires rated H (130 m.p.h.), V (more than 130 m.p.h.), or Z (more than 149 m.p.h.) be safely repaired? Yes, with some reservations.
The rubber compound used in these high-speed tires is stiffer than that of normal tires and doesn’t have enough elasticity to close a puncture without leaving a visible bulge on the outside of the tire.
4. Are ZR tires good for winter?
The short answer is no. ZR tires are not good for winter. These tires are designed for high performance, not safety and comfort. They are designed to be used in warm weather and on dry roads.
They do not have the tread or material to grip snow or ice. If you live somewhere that gets snow and ice, you should have a set of dedicated winter tires.
FAQs
What does Z mean on tires? ›
SPEED RATING Z
While it nearly always means a high performance tire for high-performing sports cars, “Z” may actually appear in the middle of a tire's size information. When it does, it represents either a maximum speed of more than 149 mph (240 kph) or 186 mph (300 kph).
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.
What does the Z mean in 225 40zr18? ›They are the same size but one is z rated which is a speed rating. The Z means it was tested up to 150mph.
What does the Z and R mean in tire size? ›The "Z" indicates a speed rating of over 149 mph. There's more to it, however, and I'll explain the rest a bit further on. "R" tells us that the tire has a radial construction. Radials are by far the most common type of passenger-car or truck tire, where the plies are situated perpendicular to the direction of travel.
What is the difference between r and Z in tire? ›The ZR rating indicates that a tire is capable of high-speed operation, while an R rating indicates that a tire is rated for speeds up to 106 mph. ZR tires are typically used on high-performance vehicles, while R-rated tires are more common on passenger cars.
What are Y or Z rated tires? ›Y ratings are for exotic sports cars with a 186 mph (300 km/h) speed limit, while the Z rating is for 149 mph (240 km/h). Tires with a Z speed rating are used on race tracks, although it's prevalent on ordinary vehicles as well. Exceptionally high speed rated tires are used on high performance vehicles.
What does the Z symbolize on vehicles? ›What does it mean? It has become a symbol of the Russian invasion, painted on military vehicles, printed on T-shirts and widely distributed through social media in support of Moscow's war.
What does the Z mean in ZR tires? ›Posted On 16 Mar 2022. The letters ZR on the sidewall relate to a tyre's speed rating, which in this case is 150mph. That means it should not be driven at speeds in excess of 150mph (240kmph) - of course, where such speeds are even legal! Before 1990, ZR was used for high-performance tyres.
What does Z mean on the back of a car? ›Many Russian civilians and business owners are putting “Z” on their cars without being forced. Other observers said that these markings act as signals to fellow Russians to identify their own vehicles in the warzone and avoid friendly fire.
What does the Z in zr18 mean? ›ZR shown on the sidewall of your tire is a reference to the tire's speed rating.. Historically, the speed rating ZR on a tire meant that the construction of the tire could reach of 150 miles or 240 kilometers per hour.
What is the Z on the side of military vehicles? ›
The Latin-script letter Z (Russian: зет, tr. zet, IPA: [zɛt]) is one of several symbols (including "V" and "O") painted on military vehicles of the Russian Armed Forces involved in the 2022 Russian invasion of Ukraine. It is speculated that the Z helps task forces distinguish themselves from other forces.
What does 225 45zr17 mean? ›So if the tire markings indicate P225/45R17 91V, it means that the height of the sidewall is 225 multiplied by 0.55 or 101.25 millimeters. The number 45 means that the height is equal to 45 percent of the width. Bigger tire ratio indicates bigger and taller tire sidewall.
What does 225 45zr18 mean? ›By way of example, in what follows, Continental decodes the sequence “225/45 R 18 95 H SSR MOE M+S”. The number “225” stands for the width of the tire in millimeters – so in this case the tire is 22.5 cm wide. The “45” that follows is the aspect ratio - the height of the tire sidewall as a percentage of its width.
Do I have to have Z rated tires? ›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.
What does the Y mean on tires? ›The final letter, in this case “Y,” corresponds to the maximum speed at which the tire can safely travel for an extended period of time. “Y” is the highest rating and it means the tire can handle speeds of up to 186 mph. “S” is the lowest speed rating, which means the tire is safe for up to 112 mph.
Can I mix ZR and R tires? ›However, if a better cornering response is what you want, installing a higher speed rated tire on your vehicle will work. Just remember, never mix and match tires with different speed ratings on your vehicle. This will cause major problems with the handling of your vehicle.
What does 97y mean on a tire? ›H - 130 mph. V - 149 mph. W - 168 mph. Y - 186 mph. (Y) - more than 186 mph.
What is the highest tire wear rating? ›Traction and temperature scores: Those scores denote a tire's wet-stopping ability and temperature resistance. For traction, AA is best, C is worst. For temperature resistance, scores range from A (best) to C. Manufacture date code: Every tire has a Department of Transportation number after the letters on the sidewall.
What are J rated tires? ›| Speed Rating | Maximum Speed |
|---|---|
| G | Up to 56 mph |
| J | Up to 62 mph |
| K | Up to 68 mph |
| L | Up to 75 mph |
H-Rated Tires: This is a perfect, average tire for most sedans and commuter vehicles. It might not seem to fit in our chart, but the tire speed rating “H” is rated for up to 130 mph. T-Rated Tires: This tire is often recommended for family sedans and vans. It's rated for up to 118 mph.
What is the Z logo? ›
The "Z" logo is believed to be Russian shorthand for “victory” and is being called “the new swastika” by critics around the world. From the beginning of the conflict in Ukraine, Russian military vehicles have been seen marked with the letter Z.
What does the Z with a line mean? ›Ƶ (lower case ƶ) The letter Z with a stroke, often used in handwriting for Z to avoid confusion with the numeral 2.
What's the meaning of the name Z? ›zed (n.) "the name of the letter Z in the alphabet," c. 1400, probably from Old French zede, from Late Latin zeta, from Greek zēta, from Hebrew zayin, letter name, literally "weapon;" so called in reference to the shape of this letter in ancient Hebrew.
What is the meaning of zr? ›Definitions of Zr. a lustrous grey strong metallic element resembling titanium; it is used in nuclear reactors as a neutron absorber; it occurs in baddeleyite but is obtained chiefly from zircon. synonyms: atomic number 40, zirconium. type of: metal, metallic element.
What does Z with double lines mean? ›Usage. The capital Latin letter Z is used in mathematics to represent the set of integers. Usually, the letter is presented with a "double-struck" typeface to indicate that it is the set of integers.
Do you need Z rated tires? ›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.
Are Z rated tires run flats? ›MICHELIN® Zero Pressure (ZP) tires provide run-flat technology that allows you to drive up to 50 miles at 50 mph with a flat tire.
Do Z rated tires wear faster? ›It depends on the tire but typically as a tire moves up in speed rating the tires tend to be designed more for high performance driving so they will wear faster. You see this mostly in the V, Z, ZR (with the W and Y sub categories) ratings and many H rated tires as well.
Why do some tires say Zr? ›The letters ZR on the sidewall relate to a tyre's speed rating, which in this case is 150mph. That means it should not be driven at speeds in excess of 150mph (240kmph) - of course, where such speeds are even legal! Before 1990, ZR was used for high-performance tyres.
What is the lowest tire rating? ›Tire speed ratings range from A (the lowest) to Y (the highest).
At what age are tires no good? ›
It may be tentative, but tires do have an expiration date. There is a general consensus that most tires should be inspected, if not replaced, at about six years and should be absolutely be swapped out after 10 years, regardless of how much tread they have left.
What are the 3 types of run flat tires? ›Run flat tyres are generally divided into three types: reinforced, self-sealing and with a support ring.
What tires don't go flat for 50 miles? ›DriveGuard tires are specifically engineered to be able to take a puncture and keep you moving. Their supportive and tough reinforced sidewalls help ensure your mobility for up to 50 miles at speeds up to 50 MPH.
Can you drive a run-flat with zero pressure? ›Reinforced sidewalls allow run flat tires to be useable even at 0 psi.
Which tires wear out the most? ›Front tyres tend to wear faster, up to 2.5 times faster on some cars. The left front tyre has it the hardest. It is the most heavily loaded and responsible for transmitting most of the steering during right hand turns.
What is the fastest tire rating? ›- The speed rating tells you the speed the tire can safely maintain over time. ...
- M — Up to 81 mph.
- N — Up to 87 mph.
- P — Up to 93 mph.
- Q — Up to 99 mph.
- R — Up to 106 mph.
- S — Up to 112 mph.
- T — Up to 118 mph.
A: ZR basically means the tire is adapted for speeds above 149mph. ZR tires includes the speed ratings V(149mph), W(168mph) and Y(186mph). The R stands for radial.
What does the SL or Zr mean on tires? ›Speed rating
The rating system uses letters from A to Z. Here, you can see that a tire with a 91V mark can them run at a maximum speed of 149 mph while carrying 615 kilograms or 1,356 pounds load. What does ZR in tire size mean? ZR or Z-rated markings mean the tires can go over 149 mph in speed.