NZ WOF TYRE GUIDE
Everything you need to know about tyre requirements for WOF certification
1.5MM
Min Tread (Standard)
4MM
Min Tread (Winter)
5%
Max Diameter Change
≤2
Load Index Difference
📋 QUICK WOF TYRE CHECKLIST
✓
Tread depth ≥ 1.5mm (4mm winter)
✓
Same size on each axle
✓
Same pattern type per axle
✓
Same carcass type per axle
✓
Within 5% of original diameter
✓
Correct speed rating for vehicle
✓
No damage, bulges, or deep cracks
✓
All markings visible
⚠️ Tyres are one of the most common reasons for WOF failure in NZ — scroll down for detailed requirements
UNDERSTANDING TYRE SIZES
▼
Learn how to read tyre sizes and what each number means. Click the icons for detailed explanations.
METRIC SIZING Most Common
Used on most passenger cars, SUVs, and vans. Example: 205/55R16 91V
Size code on sidewall
What the numbers mean
205/55R16 91V
205
Width (mm)
55
Profile %
R
Radial
16
Rim (in)
91
Load Index
V
Speed
🧮 SIZE CALCULATOR
Cross-section view (not to scale)
632mm
Overall Diameter
113mm
Sidewall Height
1985mm
Circumference
615kg
Load Capacity
504
Rev/km
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
31×10.5R15 109Q
31
Height (in)
10.5
Width (in)
R
Radial
15
Rim (in)
109
Load Index
Q
Speed
🧮 IMPERIAL SIZE CALCULATOR
787mm
Diameter (mm)
267mm
Width (mm)
203mm
Sidewall Height
1030kg
Load Capacity
💡 Common Vehicles with Imperial Sizes:
Toyota Hilux, Ford Ranger, Mitsubishi Triton (older models), Jeep Wrangler, Land Rover Defender, older 4WD wagons, and most vehicles designed for off-road use.
SPECIAL SIZE CODES
Letters that may appear in tyre sizes and what they mean for WOF compliance.
| Code | Meaning | Example | WOF Notes |
|---|---|---|---|
| P | P-Metric (Passenger) | P195/65R15 | US passenger car standard. Same-axle matching applies. |
| LT | Light Truck | LT265/70R17 | For utes and vans. Higher load capacity construction. |
| ZR | Z-Rated (240+ km/h) | 215/45ZR17 | High-speed rated. Still has speed symbol after. |
| RF / XL | Reinforced / Extra Load | 205/55R16 94V XL | Higher load capacity. Requires higher pressure. |
| C | Commercial | 195/75R16C 107R | For vans/commercial vehicles. Higher ply rating. |
| R | Radial Construction | 205/55R16 | Standard. Cannot mix with bias-ply on same vehicle. |
| D / B | Diagonal / Bias-Ply | 6.50-16 D | Older construction. Cannot mix with radials on same axle. |
| F | Run-Flat | 225/45RF17 | Self-supporting tyre. Cannot mix with non-runflat on same axle. |
⚠️ WOF Critical: Different construction types (Radial vs Bias-Ply vs Run-Flat) CANNOT be mixed on the same axle. This is an instant WOF fail.
OTHER SIZE FORMATS
Less common size formats you may encounter on older or specialty vehicles.
155R13 — "Full Profile" Format
When no profile number is shown, the tyre has an 80% aspect ratio (standard profile).
155R13 78T
- 155 = Width in mm
- R = Radial construction
- 13 = Rim diameter in inches
- 78T = Load index 78, Speed rating T
- Implied: 80% profile = 155×0.80 = 124mm sidewall
Common on: Older Japanese cars, trailers, classic vehicles
7.00R16 — Numeric Format
Used on commercial vehicles, trucks, and older 4WDs. Width is in inches with approximate conversion.
7.00R16 117/116N
- 7.00 = Width in inches (≈178mm)
- R = Radial construction
- 16 = Rim diameter in inches
- 117/116 = Single/Dual load indices
- N = Speed rating (140 km/h)
Common on: Land Cruiser 70 series, older trucks, commercial vehicles
Flotation Sizing
Large off-road tyres designed for soft terrain like sand or mud.
35×12.50R17 LT
- 35 = Overall diameter in inches
- 12.50 = Section width in inches
- R = Radial construction
- 17 = Rim diameter in inches
- LT = Light Truck rating
Common on: Modified 4WDs, Jeeps, off-road vehicles
📊 Interchangeability Table: Some imperial and metric sizes are equivalent. For example, 10/70R22.5 = 255/70R22.5 and 15R22.5 = 385/65R22.5. This applies mainly to commercial truck tyres.
⚠️ Same Axle Rule: Tyres on the same axle MUST have the same size designation. You CAN have different sizes front-to-rear (staggered fitment) as long as the diameter doesn't exceed 5% larger than original without LVV certification.
TYRE PATTERN TYPES
▼
There are three main tread pattern types. For WOF, tyres on the same axle must have the same pattern type. Click any card for detailed info.
SYMMETRICAL
Non-Directional
~60% of tyres
✓ CAN FIT ANY DIRECTION
✓ Pros
- Easy rotation — any position
- Cost-effective to manufacture
- Quiet on motorway
- Long, even tread life
✗ Cons
- Less wet grip
- Basic handling feel
- Not performance-oriented
Best for: Daily driving, city commuting, budget-conscious buyers
How to identify: No arrows or "OUTSIDE" markings on sidewall
How to identify: No arrows or "OUTSIDE" markings on sidewall
ASYMMETRICAL
Dual-Sided Design
~30% of tyres
✓ OUTSIDE MARKING
✓ Pros
- Better cornering grip
- Excellent wet handling
- Optimized for mixed conditions
- Can swap left-to-right
✗ Cons
- Must mount correct way
- More expensive
- Limited rotation options
Best for: Performance cars, SUVs, mixed wet/dry conditions
How to identify: "OUTSIDE" or "THIS SIDE OUT" marking on sidewall
⚠️ WOF Fail if: Inside wall facing outward
How to identify: "OUTSIDE" or "THIS SIDE OUT" marking on sidewall
⚠️ WOF Fail if: Inside wall facing outward
DIRECTIONAL
V-Pattern / Arrow
~10% of tyres
→ ROTATION ARROW
✓ Pros
- Superior water evacuation
- Best aquaplaning resistance
- Excellent snow/mud traction
- Aggressive styling
✗ Cons
- Cannot swap sides
- Front-to-back rotation only
- May be noisier
Best for: High-performance, wet climates, mud terrain, winter driving
How to identify: Arrow on sidewall showing rotation direction
⚠️ WOF Fail if: Fitted against rotation direction
How to identify: Arrow on sidewall showing rotation direction
⚠️ WOF Fail if: Fitted against rotation direction
🚗 PATTERN MATCHING EXAMPLES
For WOF, tyres on the same axle must match. Different patterns are allowed front-to-rear.
✅
ALL MATCH — PASS
SYM
SYM
SYM
SYM
✓ Front axle: Both symmetrical
✓ Rear axle: Both symmetrical
✅
AXLES MATCH — PASS
SYM
SYM
ASYM
ASYM
✓ Front axle: Both symmetrical
✓ Rear axle: Both asymmetrical
Different front-to-rear is OK
❌
REAR MISMATCH — FAIL
SYM
SYM
SYM
ASYM
✓ Front axle: Both symmetrical
✗ Rear axle: SYM + ASYM mixed
WOF FAIL
❌
BOTH MISMATCH — FAIL
DIR
ASYM
DIR
ASYM
✗ Front: DIR + ASYM mixed
✗ Rear: DIR + ASYM mixed
Move matching pairs together to pass
✗ WOF FAIL: Mixing different pattern types on the same axle (e.g., symmetrical + directional on front axle). Different pattern types are allowed front-to-rear but not side-to-side.
TREAD DEPTH REQUIREMENTS
▼
The legal minimum tread depth in NZ is 1.5mm for all tyres. However, different tyre types have different NEW tread depths — a mud terrain might start at 16mm while a passenger tyre starts at 8mm.
⚠️ Why Different Gauges Matter: If both a passenger car tyre and a mud terrain measure 6mm, the PC tyre is relatively new (75% remaining) while the mud terrain is over half worn (37% remaining). Always consider tyre type when assessing wear.
GROUP 1: PASSENGER CAR / HIGH PERFORMANCE (0-9mm new)
PC, HP, Grand Touring, Trailer — Typical new depth: 7-8mm
0mm
1.5mm
3mm
9mm (new)
0 - 1.5mm
WOF Fail
1.5 - 3mm
Replace Soon
3 - 9mm
Safe
GROUP 2: SUV HIGHWAY / COMMERCIAL / WINTER (0-12mm new)
SUV-HT, Light Truck HT, Van, Commercial Truck, Winter — Typical new depth: 9-10mm
0mm
1.5mm
4mm
12mm (new)
0 - 1.5mm
WOF Fail
1.5 - 4mm
Replace Soon
4 - 12mm
Safe
GROUP 3: ALL TERRAIN / MUD TERRAIN (0-19mm new)
SUV-AT, LT-AT, Rugged Terrain, Mud Terrain — Typical new depth: 12-16mm
0mm
1.5mm
6mm
19mm (new)
0 - 1.5mm
WOF Fail
1.5 - 6mm
Replace Soon
6 - 19mm
Safe
📋 TYRE CATEGORY REFERENCE
Group 1 (6-9mm new)
- Passenger Car (PC)
- High Performance / UHP
- Grand Touring (GT)
- Trailer tyres
Group 2 (8-12mm new)
- SUV Highway Terrain
- Light Truck Highway
- Commercial Van/Truck
- Winter / Snow tyres
Group 3 (10-19mm new)
- SUV All Terrain (e.g., KO2)
- Light Truck All Terrain
- Rugged Terrain
- Mud Terrain
✓ PASS — Above 1.5mm
- Tread clearly visible above TWI markers
- Groove depth measured in principal grooves
- Must be met around entire circumference
✗ FAIL — Below 1.5mm
- Tread flush with or below TWI markers
- Any bald spots around circumference
- Uneven wear exposing low areas
🔍 FINDING TREAD WEAR INDICATORS (TWI)
Look for these markers on the sidewall — they point to wear indicator bars inside the main grooves:
△ Triangle mark on sidewall
"TWI" text mark on sidewall
📏 WHERE TO MEASURE TREAD DEPTH
Measure in the principal grooves (main channels) where the TWI markers are located. The yellow highlighted areas below show correct measurement zones:
Tread depth measurement locations — measure in yellow highlighted grooves
💡 Quick Tip: When the tread wears level with the TWI bars, it's time to replace. The bars are set at 1.6mm which is just above the legal minimum of 1.5mm.
🪙 20 Cent Coin Test: Insert a NZ 20 cent coin into the main groove. If you can see the "20" on the coin, your tread is below 3mm and you should plan for replacement soon.
TYRE CRACKING — PASS VS FAIL
▼
Some surface cracking is normal with age. Here's what's acceptable and what fails WOF:
✓ PASS — Minor Cracking
- Surface crazing only
- Does not reach tyre cords
- No structural compromise
- Inspector notes it but passes
✗ FAIL — Severe Cracking
- Deep cracks reaching cords
- Cuts over 25mm long to cords
- Structural damage visible
- Significant perishing/age
✗ Also Fails WOF: Bulges or lumps (internal damage), exposed or cut cords, nails/objects embedded, string-type repairs visible from outside, significant perishing due to age, moisture or UV exposure.
📅 Age Check: Check the DOT code on your sidewall. The last 4 digits show week and year of manufacture (e.g., 2419 = week 24 of 2019). Tyres over 10 years old should be replaced regardless of appearance.
WINTER TYRE REQUIREMENTS
▼
Winter tyres have special identification and requirements in NZ.
Winter tyre identification — 3PMSF symbol and STUDLESS marking
❄️ 3 Peaks Mountain + Snowflake (3PMSF)
Official winter tyre certification symbol. Tyres with this symbol must have:
- 4mm minimum tread depth (not 1.5mm)
- Fitted to ALL 4 wheels if used
- Cannot mix with non-winter tyres
M+S (Mud & Snow)
Basic mud and snow rating. NOT the same as a true winter tyre:
- Standard 1.5mm minimum tread depth
- No requirement to fit all 4
- Less stringent testing standard
⚠️ Alpine Road Requirements: Some NZ alpine roads require chains or winter tyres during winter. Winter tyres with 3PMSF symbol can substitute for chains where signs indicate "chains or suitable 4WD vehicle".
✗ WOF Fail: Mixing winter tyres (3PMSF marked) with non-winter tyres on the same vehicle for class MA, MB, MC, MD1, MD2 or NA vehicles. If you fit winter tyres, they must be on ALL road wheels.
DAMAGE & REQUIRED MARKINGS
▼
Tyres with removed or obscured information will fail WOF. Here's what must be visible:
Info removed (circled areas) — FAIL
Info obscured by tape — FAIL
✓ Required Markings (Must Be Visible)
- Manufacturer name
- Brand name
- Model/pattern name
- Size designation
- Load rating (index or ply)
- Speed rating
- Direction of rotation (if directional)
Common Causes of Damage
- Information buffed/ground off
- Sidewall damage from kerbs
- Tape or paint covering markings
- Severe weathering/UV damage
- Chemical exposure
⚠️ TPMS Warning Light
If your vehicle has TPMS (Tyre Pressure Monitoring System), an active warning light is a WOF fail:
If this symbol is illuminated on your dashboard:
- Check and adjust tyre pressures
- If sensor removed, it must be replaced or dash light disabled
- Factory wheels removed? Sensor must be reinstalled or system properly disabled
✗ Instant WOF Fail: Any tyre marked "NOT FOR HIGHWAY USE", "NHS" (Not for Highway Service), "FOR TRAILER USE ONLY", "ADV" (Agricultural Drawn Vehicle), or "RACING PURPOSES ONLY".
COMPLETE WOF RULES SUMMARY
▼
Quick reference for all NZ WOF tyre requirements.
| Rule | Requirement | Priority |
|---|---|---|
| Tread Depth | 1.5mm minimum in principal grooves, full circumference | CRITICAL |
| Winter Tyre Tread | 4mm minimum for tyres marked with 3PMSF symbol | CRITICAL |
| Same Axle — Size | Identical size designation on same axle | CRITICAL |
| Same Axle — Construction | Same carcass type (radial, bias-ply, run-flat) | CRITICAL |
| Same Axle — Pattern | Same pattern type (symmetric, asymmetric, directional) | CRITICAL |
| Load Rating | Same-axle tyres within 2 load index points | IMPORTANT |
| Speed Rating | Must match or exceed vehicle's max speed or limit | IMPORTANT |
| Diameter Change | Max 5% larger than OE without LVV certification | IMPORTANT |
| Tread Position | Must not protrude beyond body panels/guards | STANDARD |
| Required Markings | Manufacturer, brand, size, load, speed must be visible | STANDARD |
| Damage | No bulges, deep cracks (25mm+), exposed cords, etc. | CRITICAL |
SPEED RATING REFERENCE (Complete)
| Symbol | Max Speed | Symbol | Max Speed |
|---|---|---|---|
| A1 | 5 km/h | A2 | 10 km/h |
| A3 | 15 km/h | A4 | 20 km/h |
| A5 | 25 km/h | A6 | 30 km/h |
| A7 | 35 km/h | A8 | 40 km/h |
| B | 50 km/h | C | 60 km/h |
| D | 65 km/h | E | 70 km/h |
| F | 80 km/h | G | 90 km/h |
| J | 100 km/h | K | 110 km/h |
| L | 120 km/h | M | 130 km/h |
| N | 140 km/h | P | 150 km/h |
| Q | 160 km/h | R | 170 km/h |
| S | 180 km/h | T | 190 km/h |
| U | 200 km/h | H | 210 km/h |
| V | 240 km/h | ZR | 240+ km/h |
| W | 270 km/h | Y | 300 km/h |
| (Y) | 300+ km/h |
Common NZ ratings: Q (winter/4WD), S/T (family cars), H/V (sports sedans), W/Y (performance)
LOAD INDEX REFERENCE (50-160)
| Index | kg | Index | kg | Index | kg | Index | kg |
|---|---|---|---|---|---|---|---|
| 50 | 190 | 75 | 387 | 100 | 800 | 125 | 1650 |
| 51 | 195 | 76 | 400 | 101 | 825 | 126 | 1700 |
| 52 | 200 | 77 | 412 | 102 | 850 | 127 | 1750 |
| 53 | 206 | 78 | 425 | 103 | 875 | 128 | 1800 |
| 54 | 212 | 79 | 437 | 104 | 900 | 129 | 1850 |
| 55 | 218 | 80 | 450 | 105 | 925 | 130 | 1900 |
| 56 | 224 | 81 | 462 | 106 | 950 | 131 | 1950 |
| 57 | 230 | 82 | 475 | 107 | 975 | 132 | 2000 |
| 58 | 236 | 83 | 487 | 108 | 1000 | 133 | 2060 |
| 59 | 243 | 84 | 500 | 109 | 1030 | 134 | 2120 |
| 60 | 250 | 85 | 515 | 110 | 1060 | 135 | 2180 |
| 61 | 257 | 86 | 530 | 111 | 1090 | 136 | 2240 |
| 62 | 265 | 87 | 545 | 112 | 1120 | 137 | 2300 |
| 63 | 272 | 88 | 560 | 113 | 1150 | 138 | 2360 |
| 64 | 280 | 89 | 580 | 114 | 1180 | 139 | 2430 |
| 65 | 290 | 90 | 600 | 115 | 1215 | 140 | 2500 |
| 66 | 300 | 91 | 615 | 116 | 1250 | 145 | 2900 |
| 67 | 307 | 92 | 630 | 117 | 1285 | 150 | 3350 |
| 68 | 315 | 93 | 650 | 118 | 1320 | 155 | 3875 |
| 69 | 325 | 94 | 670 | 119 | 1360 | 160 | 4500 |
| 70 | 335 | 95 | 690 | 120 | 1400 | ||
| 71 | 345 | 96 | 710 | 121 | 1450 | ||
| 72 | 355 | 97 | 730 | 122 | 1500 | ||
| 73 | 365 | 98 | 750 | 123 | 1550 | ||
| 74 | 375 | 99 | 775 | 124 | 1600 |
📊 Dual Load Ratings (e.g., 121/118)
Light truck (LT) tyres often show two load indices like 121/118. The first number (121 = 1450kg) is for single rear wheel fitment. The second (118 = 1320kg) is for dual rear wheel (dually) fitment where reduced airflow means lower capacity. Always use the appropriate rating for your vehicle's wheel configuration.
🏷️ COMMON TYRE SYMBOLS & MARKINGS
Understanding the letters and symbols on your tyre sidewall:
Construction & Type Codes
| R | Radial construction (most common) |
| D or B | Diagonal/Bias ply construction |
| F | Run-flat tyre construction |
| P | Passenger car tyre (P-metric) |
| LT | Light Truck tyre |
| C | Commercial/Cargo van tyre |
| ST | Special Trailer tyre |
| T | Temporary spare tyre |
Run-Flat Markings (by brand)
| RFT / ROF | Run-Flat Tyre (generic) |
| RSC | Run-flat System Component (BMW) |
| MOE | Mercedes Original Extended |
| AOE | Audi Original Extended |
| SSR | Self-Supporting Run-flat |
| EMT | Extended Mobility Tyre |
| ZP | Zero Pressure (Michelin) |
| DSST | Dunlop Self-Supporting |
Load & Reinforcement
| XL | Extra Load (reinforced) |
| RF | Reinforced |
| EL | Extra Load (same as XL) |
| SL | Standard Load |
| HL | High Load (EV tyres) |
| E | Load Range E (10 ply) |
| D | Load Range D (8 ply) |
| C | Load Range C (6 ply) |
Weather & Season Ratings
| M+S / M&S | Mud and Snow rated |
| ❄️ 3PMSF | Three Peak Mountain Snowflake (severe snow) |
| A/T | All Terrain |
| H/T | Highway Terrain |
| M/T | Mud Terrain |
| R/T | Rugged Terrain |
| A/S | All Season |
| UHP | Ultra High Performance |
OE (Original Equipment) Codes
| * | BMW approved |
| MO | Mercedes Original |
| AO | Audi Original |
| N0-N4 | Porsche approved |
| J | Jaguar approved |
| VOL | Volvo approved |
| T0/T1 | Tesla approved |
| RO1/RO2 | Audi Quattro/RS |
Other Important Markings
| DOT | US Dept of Transportation compliant |
| E-mark | ECE regulation compliant |
| TWI | Tread Wear Indicator location |
| OUTSIDE | Asymmetric - this side faces out |
| INSIDE | Asymmetric - this side faces in |
| ↻ Arrow | Directional rotation direction |
| TUBELESS | No inner tube required |
| MAX PSI | Maximum cold inflation pressure |
📍 Tyre Position Rule: Tyre tread must stay within body panels or mudguard extensions. For utes and SUVs (class NA/MC), tread may protrude up to 25mm if covered by a flare or wheel arch extension.
💡 Pro Tip: When buying used tyres, always check the DOT code (last 4 digits = week/year made). Even if tread looks good, tyres over 6-8 years old may have internal degradation not visible externally.
AXLE COMPATIBILITY CHECKER
▼
Check if your tyre setup meets NZ WOF same-axle requirements. Configure each position and see real-time results.
🛞 Build Your Tyre Setup
Click each position to configure
Front Left
Click to add
—
—
Front Right
Click to add
—
—
Rear Left
Click to add
—
—
Rear Right
Click to add
—
—
Drivetrain:
▲ FRONT
▼ REAR
Front Left
Front Right
Rear Left
Rear Right
📋 Compatibility Results
📋
Configure tyres to see compatibility results
