NZ WOF Tyre Guide
Everything you need to know about tyre requirements for your Warrant of Fitness
This guide covers NZ WOF tyre requirements including sizes, patterns, tread depth, and common fail reasons. Use our interactive Axle Checker tool to verify your setup before inspection.
🔢 UNDERSTANDING TYRE SIZES
Every tyre has a code on the sidewall. There are two formats — Metric (most common) and Imperial (4x4/off-road).
METRIC SIZING Most Common
Used on most passenger cars, SUVs, and vans. Example: 205/55R16 91V
Size code on sidewall
What the numbers mean
IMPERIAL SIZING 4x4 / Off-Road
Used on 4x4s, trucks, and off-road vehicles. Example: 31/10.5R15 109Q
Size code on sidewall
What the numbers mean
Size Tolerance for WOF
When fitting different sized tyres, the overall diameter must not exceed 5% larger than original. Going outside this tolerance requires LVV certification.
Allowed Diameter Change
🔄 TYRE PATTERN TYPES
There are three main tread pattern types. For WOF, tyres on the same axle must have the same pattern type.
SYMMETRICAL
Non-Directional
- Left and right sides are identical
- Can be fitted any direction
- Easy to rotate between positions
- Most common, cost-effective option
ASYMMETRICAL
Dual-Sided Design
- Left and right sides are different
- Outer edge for cornering grip
- Inner edge for wet performance
- Must be fitted correct way out
DIRECTIONAL
V-Shaped / Arrow Pattern
- V-shaped tread pointing forward
- Channels water away quickly
- Must rotate front-to-back only
- Excellent wet weather grip
What Does Your Tread Look Like?
Compare your tyres to real photos at every wear stage
📏 TREAD DEPTH & WEAR INDICATORS
NZ legal minimum is 1.5mm (4mm for winter tyres). Here's how to find wear indicators:
Finding TWI (Tread Wear Indicator) Marks
Look for a small triangle △ or "TWI" text on the sidewall — this points to the wear indicator location.
△ Triangle mark
"TWI" text mark
Where to Measure Tread Depth
Measure in the principal grooves (the main channels) where wear indicators are located. The yellow lines show measurement width:
🔍 TYRE CRACKING — PASS VS FAIL
Some cracking is normal with age. Here's what's acceptable and what's not:
✓ PASS — Minor Cracking
Surface cracking that doesn't reach the cords. Note it but don't reject.
✗ FAIL — Unacceptable Cracking
Deep cracks, exposed cords, or structural damage. Requires replacement.
❄️ WINTER TYRE IDENTIFICATION
Winter tyres have special requirements in NZ. Here's how to identify them:
🚫 INFORMATION REMOVED OR OBSCURED
Tyres with removed or hidden markings will fail WOF:
Info removed (circled)
Info obscured by tape
TPMS Warning Light
If your vehicle has TPMS (Tyre Pressure Monitoring System), this warning light must not be active:
📋 NZ WOF TYRE RULES SUMMARY
Same Axle Requirements
- Same size designation
- Same carcass type (radial, cross-ply, run-flat)
- Same tread pattern type (directional, asymmetric, symmetric)
- Load indices within 2 of each other
Tread Depth
- Standard tyres: 1.5mm minimum
- Winter tyres: 4mm minimum
- Measured in principal grooves
- Around full circumference
Speed Rating
- Must match or exceed vehicle's max speed
- Or the speed limit (if lower)
- Check sidewall for rating letter
Size Changes
- Up to 5% larger: Usually OK
- Over 5% larger: Needs LVV certification
- Tread must not protrude beyond guards
Speed Rating Reference
| Rating | Max Speed | Typical Use |
|---|---|---|
| N | 140 km/h | Temporary spare tyres |
| Q | 160 km/h | Winter tyres, 4WD |
| S | 180 km/h | Family sedans, wagons |
| T | 190 km/h | Standard passenger cars |
| H | 210 km/h | Sport sedans, coupes |
| V | 240 km/h | Sports cars |
| W | 270 km/h | High-performance vehicles |
| Y | 300 km/h | Exotic supercars |
Common Load Index Reference
| Index | kg | Index | kg | Index | kg | Index | kg |
|---|---|---|---|---|---|---|---|
| 75 | 387 | 85 | 515 | 95 | 690 | 105 | 925 |
| 76 | 400 | 86 | 530 | 96 | 710 | 106 | 950 |
| 77 | 412 | 87 | 545 | 97 | 730 | 107 | 975 |
| 78 | 425 | 88 | 560 | 98 | 750 | 108 | 1000 |
| 79 | 437 | 89 | 580 | 99 | 775 | 109 | 1030 |
| 80 | 450 | 90 | 600 | 100 | 800 | 110 | 1060 |
| 81 | 462 | 91 | 615 | 101 | 825 | 111 | 1090 |
| 82 | 475 | 92 | 630 | 102 | 850 | 112 | 1120 |
| 83 | 487 | 93 | 650 | 103 | 875 | 113 | 1150 |
| 84 | 500 | 94 | 670 | 104 | 900 | 114 | 1180 |
🔧 AXLE COMPATIBILITY CHECKER
Check if your tyres meet NZ WOF same-axle requirements. Configure each position and see real-time compatibility results.
🛞 Build Your Tyre Setup
Click each position to configure the tyre
📋 Compatibility Results
Images and information sourced from Waka Kotahi NZ Transport Agency
Vehicle Inspection Requirements Manual (VIRM) — In-service certification (WoF and CoF)
