What tread depth do I need to pass a WoF in NZ?
At least 1.5 mm of tread in the main grooves, all the way around the tyre. The tyre must also be free of cracks, bulges, cuts and exposed cords. That's the legal minimum, not a safe target: grip in the wet drops off quickly once tread falls below about 3 mm.
How do I check tread depth myself?
Most tyres have small raised bars, called tread wear indicators, moulded into the main grooves. When the tread wears down level with those bars, the tyre is at the 1.5 mm legal limit and needs replacing. A cheap tread depth gauge gives an exact reading. Check several points around each tyre, because wear is often uneven.
Why is 3 mm worth knowing?
Tread channels water away from the contact patch. As it wears, the tyre is more likely to ride up on standing water and lose grip. Wet-weather performance drops off quickly below about 3 mm, so many drivers replace tyres before they reach the legal limit.
What else can fail a WoF on tyres?
- Cracks, cuts or bulges in the tread or sidewall.
- Exposed cords or steel belts.
- Tyres on the same axle that don't match in size or type.
- Uneven wear that takes part of the tyre below 1.5 mm.
What happens if my car fails?
Around 40% of vehicles fail their WoF the first time, often for small things. You have 28 days to fix the problem and get a free recheck at the same inspecting station.
Not sure what you need?
Call in for a free tyre safety check at 18 Durham Street South, Monday to Friday, 8am to 5pm. We'll tell you straight if it needs work.
Common questions
Does a WoF check how old my tyres are?
No. A WoF checks the condition of your tyres, not their age. An old tyre can still fail if the rubber has cracked or perished.
Can I mix different tyres on the same axle?
No. Tyres on the same axle should match in size and type. Mismatched tyres on one axle are a common reason for a WoF failure.
What happens if my car fails its WoF on tyres?
You have 28 days to replace or repair the tyres and get a free recheck at the same inspecting station.
