How often to check tyre pressure and tread depth in NZ, the 1.5mm legal minimum for a WOF, and why waiting until you hit it is a risky habit.
Check tyre pressure monthly and before long trips, using the figure on your vehicle placard or in the handbook. Check tread at the same time. The legal minimum in New Zealand is 1.5mm and a tyre below it fails a WOF, but wet-weather grip drops significantly below 3mm, so replace tyres before reaching the limit.
Tyre pressure and tread depth are the two easiest checks you can do on your own vehicle, and in NZ they are also two of the most commonly missed until a WOF inspector points them out.
This guide gives you a monthly routine, explains what the 1.5mm legal minimum actually means, and shows how to read uneven wear so you fix the cause instead of just replacing the tyre.
New Zealand Police recommend checking tyre inflation once a month, and it is wise to check before any long trip or when carrying a heavy load. Tyres lose pressure slowly even with no puncture, and colder weather lowers it further, so a tyre that was right a month ago may be low now.
Check when the tyres are cold, ideally before you have driven that day. Use the pressure shown on the vehicle placard (often on the door jamb or fuel flap) or in the owner's handbook. Do not use the number moulded on the tyre sidewall, because that is the tyre's maximum rating rather than your vehicle's recommended pressure. The Tyre Awareness Week site at tyresafety.org.nz explains how to find the right pressure and inflate tyres.
The legal minimum tread depth is 1.5mm, and New Zealand Police confirm a tyre with less will not pass a Warrant of Fitness inspection. They also point out that wet-weather grip falls away significantly once tread drops below 3mm, so 1.5mm is a fail line, not a comfortable target.
Wear that is heavier on one edge, in the centre, or on one tyre only is a clue about the cause. Heavy wear on one edge often points to wheel alignment or suspension wear. Wear in the centre suggests over-inflation, and wear on both edges suggests under-inflation. Scalloped or patchy wear can mean worn shock absorbers or unbalanced wheels.
If you replace the tyre without fixing the cause, the new one will wear the same way. Ask a tyre shop to check alignment and suspension at the same time.
Set a reminder on the first weekend of each month and run through the same short list.
Get a professional check when you notice vibration, the car pulling to one side, uneven wear, or repeated pressure loss in one tyre. Many tyre shops will check pressure and tread quickly, and they can inspect alignment and suspension, which are hard to judge in a driveway.
TopChoice checks each listed business against the NZ Companies Office and NZBN register, its Google Business Profile and its reviews, and excludes lead-generation sites and operators it cannot verify. Our Top 5 tyres and wheel alignment lists are a vetted place to start.
See our independently researched Top 5 Tyres & Wheel Alignment in Christchurch.
Compare vetted local businesses for this job.
1.5mm. New Zealand Police state that a tyre below this will not pass a Warrant of Fitness inspection. Grip in the wet falls significantly once tread is below 3mm, so replace tyres earlier.
Once a month, and before any long trip, according to New Zealand Police. Check when the tyres are cold for an accurate reading.
Use your vehicle manufacturer's recommended pressure from the placard or owner's handbook. The figure on the sidewall is the tyre's maximum rating, not the right pressure for your car.
Uneven wear is often caused by wheel alignment, suspension wear, or incorrect pressure. Have the cause checked before buying a replacement, otherwise the new tyre will wear the same way.
Not sure what a panelbeater does after a car accident in NZ? Learn how assessment, insurer approval, repairs and handover work, and what to ask first.
Read more →How often to service your car in NZ: follow the manufacturer's schedule, know the difference between a service and a WoF, and when to service sooner.
Read more →What a building quote in NZ must cover once a job reaches $30,000, plus the terms worth checking on smaller jobs so a price does not blow out later.
Read more →Put your business in the spotlight with a prominent placement and a dedicated profile on the exact pages people in your city are searching right now.
Explore Spotlight