NZ WoF Tyre Requirements — Complete 2026 Guide

Every New Zealand vehicle must pass a Warrant of Fitness (WoF) inspection to legally drive on NZ roads. Tyres are one of the most common WoF failure points — and many NZ drivers are caught off guard by requirements they didn’t know existed.

This guide covers every WoF tyre rule in New Zealand, explained clearly. Bookmark it before your next WoF inspection.

Key Facts — At a Glance

Minimum tread depth: 1.5mm across all principal grooves, all the way around the tyre
Winter tyre minimum tread depth: 4mm
Same-axle rule: Tyres on the same axle must be the same size and same tread pattern type
Damage failures: Cuts over 25mm reaching cords, bulges, exposed cords, embedded objects, significant perishing
Penalty for non-compliance: Fines, demerit points, and possible vehicle impoundment

Tread Depth — The Most Common WoF Failure

What is the legal minimum?

1.5mm — measured in the principal grooves that contain the tyre’s moulded tread-depth indicators.

This measurement must be:

Maintained across all principal grooves (not just some of them)
Present around the complete circumference of the tyre

How inspectors check it

WoF inspectors look for the tread wear indicators (TWIs) — small raised bars moulded into the bottom of the tyre’s main grooves. When your tread wears down to the level of these bars, you are at the legal minimum of 1.5mm.

For tyres without moulded tread-depth indicators (some retreads and vintage tyres), the old standard applies: 1.5mm across three-quarters of the tread width, all the way around the tyre.

Legal minimum vs safe minimum — they’re not the same

Tread Depth	Status	Wet Braking Impact
8mm	New tyre	Baseline
3mm	Recommended replacement threshold	+25% longer wet braking distance vs new
1.5mm	Legal minimum (WoF pass/fail)	Significantly longer — dangerous in heavy rain
Below 1.5mm	FAIL — illegal to drive	Extremely dangerous

NZ safety experts recommend replacing tyres at 3mm — not waiting until 1.5mm. At 3mm, your wet braking distance is already 25% longer than a new tyre. At 1.5mm, the difference is even greater.

Winter tyres — different rules

Tyres marked with the M+S or snowflake symbol (dedicated winter tyres) require a minimum of 4mm tread depth to pass a WoF inspection. This higher threshold reflects the greater safety risk of worn winter tyres in snowy or icy conditions.

The Same-Axle Rule

This is the rule that surprises many NZ drivers when they try to mix brands or sizes.

WoF Rule: Tyres on the same axle must have:

The same tyre size (e.g., both 225/45 R17)
The same tread pattern type

What counts as tread pattern types?

Asymmetric — different inner and outer tread (must match on same axle)
Directional — V-shaped grooves with a rotation arrow (must match on same axle)
Symmetric/Standard — conventional tread pattern (can mix brands if same size)

What this means in practice

You can fit two different brands on the same axle if they are the same size and the same tread pattern type
You cannot fit an asymmetric tyre on one side and a directional tyre on the other side of the same axle
Different sizes on the same axle is always a fail — even by 5mm

Important: Front and rear axles can have different sizes *only if* the vehicle manufacturer specifies a staggered fitment (common on sports cars like Porsche). If your car doesn’t have factory-staggered fitment, front and rear must also be the same size.

Tyre Damage — What Causes a WoF Failure

Your tyre fails WoF inspection for damage if any of the following are found:

Damage Type	WoF Verdict
Cuts or cracks in sidewall or tread over 25mm long that reach the cords	FAIL
Bulges anywhere on the tyre (sidewall or tread)	FAIL
Exposed cords visible through tread or sidewall	FAIL
Nails, screws, or objects embedded in the tyre	FAIL
Significant perishing or cracking of the rubber	FAIL
Tread separation or delamination	FAIL
Visible fabric or steel cord through any crack	FAIL

What inspectors won’t automatically fail

Minor surface cracking in the sidewall that doesn’t reach cords (common in older tyres, inspector judgement)
Small plugged punctures in the tread (if properly repaired and not in the sidewall)
Uneven tread wear (if still above 1.5mm everywhere) — but this does indicate an alignment or inflation problem worth addressing

Tyre Age — A Common Trap

NZ WoF regulations don’t specify an automatic age limit for tyres, but inspectors can fail a tyre for “significant perishing” — which typically becomes a risk after 7–10 years regardless of tread depth.

How to check your tyre age:

Look at the DOT code on your tyre sidewall. The last four digits tell you the week and year of manufacture.

Example: DOT XXXX 2318 = manufactured in the 23rd week of 2018

Tyre Age	Recommendation
0–5 years	Safe — normal use
5–7 years	Consider replacement, especially in high-UV/heat environments
7–10 years	Replace — rubber degrades even if tread is adequate
10+ years	Replace immediately — serious safety risk

NZ-specific note: NZ’s UV intensity (especially in summer) accelerates tyre rubber degradation. UV and ozone exposure causes the rubber to crack and harden. This makes the 7-year replacement recommendation more relevant here than in European climates.

Tyre Pressure — Not a Direct WoF Check, But…

WoF inspectors don’t directly measure tyre pressure during the inspection. However:

Incorrect pressure causes uneven tread wear — which *can* cause a tread depth failure
Severely underinflated tyres can cause sidewall damage (bulges) that *will* cause a failure
TPMS (Tyre Pressure Monitoring System) lights on your dashboard — if illuminated during inspection — may cause concern but typically aren’t a direct WoF fail for the tyre itself

Recommended practice: Check and set correct tyre pressure at least monthly. Your vehicle’s recommended pressure is in the driver’s door jamb sticker and owner’s manual — not on the tyre sidewall (that shows maximum pressure, not recommended).

Fines and Penalties

Driving on tyres that fail WoF requirements is a serious offence in New Zealand:

Fine: Up to $400 per offence
Demerit points: Applied to your licence
Vehicle impoundment: Possible for repeat offenders or serious safety breaches
Insurance implications: Driving an unwarranted vehicle may affect your insurance claim validity

Important: Even if your WoF hasn’t expired, you can be stopped and fined by Police for driving on visibly unsafe tyres (cuts, bulges, exposed cords) at any time. The WoF system is a periodic check — it doesn’t exempt you from responsibility between inspections.

How to Pass Your Next WoF Tyre Inspection — Checklist

Before booking your WoF:

[ ] Check tread depth with a tread depth gauge — aim for 2mm+ (gives safety buffer above 1.5mm legal minimum)
[ ] Inspect all four sidewalls for bulges, cuts, cracks, or embedded objects
[ ] Verify tyre size is the same on each axle
[ ] Check tyre age (DOT code) — replace if over 7 years old
[ ] Inflate all four tyres to the correct pressure (in driver’s door jamb)
[ ] Ensure TPMS warning light (if equipped) is not illuminated

Frequently Asked Questions

Q: Can I get a temporary WoF pass if my tyres are just below 1.5mm?

No. The 1.5mm threshold is a hard pass/fail. Your vehicle fails and you must replace the tyres before a re-inspection.

Q: My car failed WoF for tyres. How long do I have to fix it?

There is no grace period — your car is no longer legally warranted from the point of failure. You should not drive it (except directly to a tyre shop to get new tyres fitted). After the new tyres are fitted, you can return for a re-inspection. Not sure which tyres to buy? See our Best Budget Tyres NZ guide for safe, affordable options.

Q: Do all four tyres need to match?

Front and rear axles can legally have different brands *and* different sizes (staggered fitment), as long as each axle has matching size and pattern type. But check: does your car actually have factory-staggered fitment? Most standard passenger cars don’t.

Q: Can a run-flat tyre pass WoF if it’s been driven on flat?

No. A run-flat tyre that has been driven at zero pressure must be replaced — it sustains internal structural damage that cannot be seen externally but makes the tyre unsafe. This is a WoF failure if the inspector identifies evidence of flat running (kinking, internal separation visible on inflation).

Q: What about spare tyres — do they need to meet WoF standards?

Only if the spare is mounted and being used as a regular road tyre. A spare in the boot does not need to meet WoF tread depth requirements, but if you’re driving on it, it must be roadworthy.

Sources

NZTA Vehicle Inspection Portal — Guidance for vehicle inspectors — tyre tread depth — vehicleinspection.nzta.govt.nz — accessed 2026-05-31
Tyre Dispatch NZ WoF Guide — tyredispatch.co.nz/pages/wof-tyre-guide — accessed 2026-05-31
TyreHub NZ — Tyres and WoF Requirements — tyrehub.co.nz — accessed 2026-05-31
Servo NZ — WoF Minimum Tread Depth — servo.nz — accessed 2026-05-31
Kiwi Car Loans — Tyre Tread Depth Guide — kiwicarloans.co.nz — accessed 2026-05-31
Tyre Power NZ — Tread Depth Guide — tyrepower.co.nz — accessed 2026-05-31

Ideogram Image Prompts for This Page

Hero image:

> Close-up of a WoF inspector examining a car tyre with a tread depth gauge, professional setting in a NZ inspection garage, clean modern workshop, focused lighting on the tyre, photorealistic style, no text

Tread depth diagram image:

> Professional technical diagram showing four tyre cross-sections at different tread depths (new/3mm/1.5mm/worn), clean flat design with measurement labels, teal and dark grey color scheme, educational infographic style, white background

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NZ WoF Tyre Requirements – Complete 2026 Guide