Tyre Speed Rating Guide

Understanding tyre speed ratings is crucial for both safety and legal compliance in New Zealand. This comprehensive guide provides NZ drivers with a full tyre speed rating chart, explains Warrant of Fitness (WOF) rules, and demystifies “Z” vs “ZR” tyres and other speed codes. You’ll also get practical advice on choosing the right speed-rated tyres for your vehicle – whether it’s a passenger car, high-performance sports car, 4WD/SUV, or a light commercial – ensuring you meet all WOF NZ requirements and drive with confidence.

What Are Tyre Speed Ratings?

A tyre’s speed rating is an alphabetic code (usually a letter) that indicates the maximum speed the tyre can safely sustain when carrying its specified load. For example, a tyre with a “T” speed rating is approved for speeds up to 190 km/h, while an “H” rated tyre is safe up to 210 km/h. Generally, the further along the alphabet the letter, the higher the speed capability (with a few exceptions like H). Higher speed ratings often mean the tyre is built with a softer compound or stiffer construction to handle heat and stress at high speeds. These ratings reflect tested maximums, not recommended driving speeds – they indicate capability under ideal conditions, not a target to reach on public roads.

How to Find Your Tyre’s Speed Rating

Every tyre’s speed rating is printed on its sidewall as part of the tyre size/service code. Look for the letter at the end of the sequence – that letter is the speed symbol.

For example, in a code like 205/60R16 92H, the “H” at the end denotes a 210 km/h speed rating.

You can also find the required minimum speed rating for your vehicle on the factory tyre placard, usually located:

• Inside the driver’s door jamb

• Inside the fuel flap

• Inside the glove box

Additionally, your owner’s manual will specify the minimum speed rating your tyres must have. If your tyres have a lower speed rating than specified, they must be replaced to maintain safety and legality.

Tyre Speed Rating Chart (NZ)

Below is a complete NZ speed rating chart showing each letter and its maximum approved speed:

✅ Note: You can safely mix ZR and non-ZR tyres on the same axle as long as both tyres meet or exceed the vehicle’s minimum speed rating. For example, a 205/55R16 91V (non-ZR) and a 205/55ZR16 91W (ZR-marked) can be used together if both are speed-rated above your car’s requirement.

Always ensure both tyres are rated high enough for the vehicle’s specifications to maintain WOF compliance and safe handling.

Z vs ZR Tyres – Understanding High-Speed Ratings

You may come across tyre sizes like 245/40ZR18. The “ZR” here historically meant the tyre was approved for speeds over 240 km/h. However, modern tyres with this marking will still show an exact rating like W or Y:

• 91W = 270 km/h

• 91Y = 300 km/h

• (Y) = Above 300 km/h

So, while “ZR” is still used in some size codes, it is now more of a legacy or branding indicator, and the true speed capability is confirmed by the W/Y code following the load index.

✅ Note: You can safely mix ZR and non-ZR tyres on the same axle as long as both tyres meet or exceed the vehicle’s minimum speed rating. For example, a 205/55R16 91V (non-ZR) and a 205/55ZR16 91W (ZR-marked) can be used together if both are speed-rated above your car’s requirement.

Always ensure both tyres are rated high enough for the vehicle’s specifications to maintain WOF compliance and safe handling.

Speed Ratings and WOF Requirements in NZ

In New Zealand, WOF (Warrant of Fitness) rules require that your tyres meet or exceed the speed rating recommended by the vehicle’s manufacturer.

Key Points:

• You must not fit tyres with a lower speed rating than what is listed on the vehicle’s placard or in the manual.

• Even though NZ’s open-road limit is 100 km/h, most passenger cars require tyres rated at 180–210 km/h or higher.

• Using under-rated tyres is illegal, may fail a WOF, and can invalidate your insurance.

• The only exception (rare in NZ) is for winter tyres, which may be Q-rated (160 km/h) and used seasonally in colder climates.

Bottom line: Always match or exceed your manufacturer’s original speed rating. For example, if your car requires H-rated tyres, you can use H, V, W, or Y – but not T, S, or lower.

Mixing Tyre Speed Ratings – What’s Allowed?

Under NZ WOF rules:

• You can have tyres with different speed ratings on the same vehicle, as long as each tyre meets the minimum required speed rating.

• Tyres on the same axle can have different ratings (e.g. V and W), but this is not recommended.

Best Practice:

• Use matching speed ratings on each axle for consistent handling.

• If you must mix, put the higher-rated tyres on the rear axle.

• Your car’s effective speed capability is limited by the lowest-rated tyre.

Example: If you have 3x W-rated tyres and 1x H-rated tyre, your car is only rated for 210 km/h, not 270.

Choosing the Right Speed Rating by Vehicle Type

Passenger Cars

• Typical ratings: S, T, H (180–210 km/h)

• Ideal for everyday driving and legal speeds in NZ

• Higher ratings (V, W) offer no real benefit for standard road use

Performance Vehicles

• Typical ratings: V, W, Y

• Required for sports cars and high-performance vehicles

• Designed for better grip, heat resistance, and stability at speed

SUVs and 4WDs

• City SUVs: Often H or V

• Off-road tyres (All-Terrain or Mud-Terrain): Often Q or S

• Make sure the speed rating matches your use – Q-rated tyres are fine for most 4WDs

Light Commercial Vehicles

• Typical ratings: N, P, Q (140–160 km/h)

• Prioritize load index and durability over high speed

• LT (Light Truck) tyres often have lower speed symbols but higher load capacity

Final Advice

If you’re unsure:

• Check your tyre placard or owner’s manual

• Consult a trusted tyre retailer

• Always meet or exceed the required speed rating

• Stick with the same rating across all tyres if possible

• For optimal safety and WOF compliance, never downgrade your speed rating