NZ WOF AXLE COMPATIBILITY INTERACTIVE TOOL
Free tool from the Tyre Dispatch workshop.
Check your tyre setup
Click any wheel position to add a tyre, or drag filled tyres between positions to swap them. Results update as you go, and every fail names the rule behind it. Not sure where to start? Load the example setup and watch the rules fire. If the vehicle was registered in NZ before 1 October 2002, or is 30 or more years old, tick the box under the drivetrain buttons so the whole-vehicle carcass rule is applied the way the manual applies it.
On one axle, both tyres must match on size designation, carcass type and tread pattern type, with load indices within 2 points of each other (or the same ply rating). Across axles you may run different sizes and patterns, but carcass type must match across the whole vehicle on nearly every car, SUV, ute and van first registered or re-registered here from 1 October 2002, and winter tyres go on all road wheels or none. Speed ratings are not an axle rule at all.
In this guide
What the manual actually says about matching tyres
These requirements come from the Land Transport Rule: Tyres and Wheels 2001, inspected under the NZTA Vehicle Inspection Requirements Manual, section 10-1. The checker above implements them as written.
On the same axle
- Same size designation. 205/55R16 beside 215/55R16 is a fail, whatever the brands. The tyre size guide explains every part of the marking.
- Same carcass type. Radial, bias/cross-ply and run-flat are different carcass types. A run-flat beside a standard radial fails.
- Same tread pattern type. The manual's categories are normal highway (symmetrical), asymmetric, directional, traction and winter tread. One axle, one category.
- Load indices within 2 points, or the same ply rating. 91 with 93 passes; 91 with 94 needs matching ply ratings to pass. What each index carries is in the load rating guide.
Across the vehicle
- One carcass type on all wheels for cars, most SUVs, utes and vans (vehicle classes MA, MB, MD1 and NA) first registered or re-registered in New Zealand from 1 October 2002, which is nearly everything in daily use. Earlier registrations, vehicles 30 years old or more, and other classes (including class MC off-road vehicles, which covers many large 4WD wagons) only need each axle to match.
- Winter tyres on all road wheels, or none. A winter pair on one axle with normal tyres on the other is a fail in itself. The spare is not a road wheel, so it does not count.
- Different sizes and pattern types on different axles are allowed. Staggered setups are legal; on AWD and 4WD the driveline is the thing to worry about, not the WOF.
- Speed ratings are not on the matching list. Each tyre just needs a rating at or above the speed limit for the vehicle, or the vehicle's own top speed if that is lower.
Coming 1 November 2026: two-yearly WOF inspections begin for light vehicles registered from November 2019, with 2013 to 2019 registrations following from November 2027, and the infringement fee for non-compliant tyres rises from $150 to $350, with court fines up to $1,000. The matching rules on this page are unchanged, but with twice as long between inspections, checking your own setup matters more than it ever has.
Source: VIRM section 10-1, tyres and wheels, checked against the live manual in August 2026.
How to spot each rule on the tyre itself
Every check above starts with something written or moulded on the sidewall. Here is what to look for before you enter your setup. Apart from the labelled size diagram, every image is a tyre that has been through our own workshop.
Tread pattern types
Every pattern type with its share of the NZ market is in the tread pattern guide.
Size and load index live in one string
Run-flats
A run-flat counts as its own carcass type. One run-flat beside a standard radial on an axle is a fail, and because the whole-vehicle carcass rule covers nearly everything registered here from 1 October 2002, most cars are effectively all four run-flat or none. Worth knowing before replacing one tyre at a time on a European car that came on run-flats from the factory.
Ply ratings and dual load indices
Light-truck and 4WD tyres often state their strength two more ways. A ply rating (10PR, or a load range letter like E) is the older strength scale, and it earns its own branch of the load rule: a pair whose load indices are 3 or more apart still passes when both tyres carry the same ply rating. The checker accepts this, so enter the ply rating on each tyre when it is moulded there. A dual load index like 121/118 gives two numbers: the first is for a single fitment, the second for twinned wheels on one hub. On a normal ute or van running single wheels, the first number is the one to enter.
Neither reaches across the vehicle. The load rule is same-axle only, so a ute with 10-ply tyres on the rear and 6-ply on the front passes, as long as each axle's own pair agrees and every tyre is rated for the load its axle carries.
Mixed tyre setups, at a glance
The situations we get asked about most. Use the tool above for your exact combination, and find our other calculators on the tyre tools hub.
| Setup | Same axle | Different axles |
|---|---|---|
| Different tyre sizes | Fail | OK |
| Different brands, same size, pattern and carcass type | OK | OK |
| Directional beside symmetrical | Fail | OK |
| Radial beside bias/cross-ply | Fail | Fail on registrations from Oct 2002 |
| Run-flat beside standard radial | Fail | Fail on registrations from Oct 2002 |
| Different speed ratings | OK | OK |
| Load indices 2 apart or less | OK | OK |
| Load indices 3 or more apart, different ply ratings | Fail | OK |
| Winter mixed with normal, anywhere on the vehicle | Fail | Fail |
Mixed speed ratings pass the matching rules either way, but the vehicle is limited in practice by its slowest tyre: the speed rating guide covers what the letters are worth.
Tread minimums, and the winter exception
Whatever the matching rules say, every tyre also has to meet its tread minimum to pass.
Normal tyres: 1.5mm
Within all principal grooves that carry moulded tread-depth indicators, around the whole circumference. Our workshop advice is to plan replacement from 3mm, because wet grip falls away well before the legal floor.
Winter tyres: 4mm
Winter tread has its own minimum. Below 4mm a winter tyre is a WOF fail even though a normal tyre at the same depth would pass. Common catch on Japanese imports arriving on part-worn winter rubber.
Guessing depth by eye does not work: measure it, or come in and we will. For what wear actually looks like at each depth, with photographs from our own inspections, see the tread depth guide and gallery.
Common questions about axle compatibility
Can I have different-sized tyres on the same axle?
No. Tyres on one axle must carry the same size designation, so a 205/55R16 next to a 215/55R16 fails. Different sizes on different axles are allowed, which is how staggered setups are legal, as long as each axle matches side to side and the whole vehicle keeps one carcass type. On AWD and 4WD vehicles, mismatched diameters front to rear can also damage the driveline, so check the handbook before staggering.
Can I have different tyres on the front and rear?
Usually yes. The matching rules work axle by axle, so different sizes, brands and tread pattern types front to rear all pass, as long as each axle matches side to side. Two rules reach across the whole vehicle: carcass type (radial, bias/cross-ply or run-flat) must match on all wheels for nearly every vehicle first registered or re-registered here from 1 October 2002, and winter tyres go on all road wheels or none. On AWD and 4WD vehicles, keep front and rear diameters close for the driveline's sake, even though the WOF does not measure that.
Can I mix radial and cross-ply tyres?
Not on the same axle, and on most vehicles not at all. The axle rule bans mixed carcass types side by side. On top of that, nearly every vehicle first registered or re-registered in New Zealand from 1 October 2002, which is nearly every car, SUV, ute and van in daily use, must carry the same carcass type on all wheels (vehicles 30 years old or more are exempt from the whole-vehicle rule). And note what counts as a carcass type: radial, bias/cross-ply, and run-flat. A run-flat next to a standard radial on one axle is a fail, which surprises a lot of people replacing one tyre at a time.
Can I mix run-flat and normal tyres?
Not next to each other, and on most cars not at all. A run-flat counts as its own carcass type, so one beside a standard radial on an axle fails the same-axle rule. On nearly every vehicle first registered or re-registered here from 1 October 2002 the whole-vehicle carcass rule applies on top, which makes it all four run-flat or none. The markings are easy to miss: DSST, RSC, ROF, ZP, EMT or just a flat-tyre symbol, so check the sidewall before replacing one tyre at a time.
Can I mix directional and symmetrical tyres on the same axle?
No. Directional, symmetrical and asymmetric are different tread pattern types, and one axle must carry one type. Across axles you may mix, so asymmetric front with symmetrical rear passes. The full pattern breakdown lives in the tread pattern guide.
Do load ratings need to match on the same axle?
The manual accepts an axle when the tyres share the same ply rating or their load indices differ by no more than 2. So 91 beside 93 passes, and 91 beside 94 fails unless both tyres carry the same ply rating. The checker above accepts the same escape: when the indices are more than 2 apart, enter the ply rating on each tyre. What each number carries in kilograms is on the load rating chart.
Do front and rear load ratings or ply ratings have to match?
No. The load rule is same-axle only, so a ute running 10-ply tyres on the rear and 6-ply on the front passes. Each axle's own pair must sit within 2 load index points or share a ply rating, and every tyre needs to be rated for the load its axle actually carries, but nothing requires front and rear to match each other. The load rating guide explains how to read the numbers.
Do speed ratings need to match on the same axle?
No. Speed rating is not part of the axle matching rule at all. Each tyre only needs a rating at or above the lower of the speed limit and the vehicle's own top speed. Your vehicle is still limited by its slowest-rated tyre in practice. The full picture, including what the letters are worth paying for, is in the speed rating guide.
Can I mix winter and normal tyres?
No. If any winter tyre is fitted, winter tyres must be on all road wheels. A winter pair on one axle with normal tyres on the other is a WOF fail. Winter tyres also carry their own tread minimum of 4mm instead of 1.5mm, which matters on Japanese imports that often arrive wearing part-worn winter rubber.
Can I have different brands on the same axle?
Yes. Brand and model are not inspected. As long as both tyres match on size, carcass type and pattern type, and the load indices are within 2, mixed brands pass. We still match pairs whenever we can, because grip and wear stay consistent side to side, but that is workmanship rather than law.
Do tyres have to be replaced in pairs in NZ?
Not by law. A single new tyre beside a part-worn one passes the WOF as long as the pair still matches on size, carcass type and pattern type, with load indices within 2 or the same ply rating. We still recommend replacing in pairs on the same axle, because a big tread difference side to side changes how the car grips and brakes in the wet, but that is workshop advice, not a legal requirement.
Does passing this checker guarantee a WOF pass?
No, and it should not. This tool checks the written matching rules: sizes, carcass types, pattern types, load indices, winter placement and tread depth. An inspector also judges condition, meaning damage, perishing, exposed cords, repairs and more, which no calculator can see. For the full inspection picture, read the WOF tyre guide or bring the car in.
- NZTA Vehicle Inspection Requirements Manual, in-service WOF and CoF, section 10-1, tyres and wheels. The checker implements the same-axle rule (reason for rejection 1), the whole-vehicle carcass rule for registrations from 1 October 2002 (rejection 2), winter tyre placement (rejection 3), the load index allowance (rejection 4) and the tread minimums (1.5mm, rejection 15; 4mm for winter tyres, rejection 16), all verified against the live manual (page amended 1 April 2023) in August 2026.
- NZTA news, changes to light vehicle inspections from 1 November 2026: WOF frequency moves and the tyre infringement fee increase. None of it changes the matching rules above.
- Land Transport Rule: Tyres and Wheels 2001, the rule the VIRM inspects against.
- First-party: the scenarios, the workshop advice and the sidewall photographs on this page come from our own fitting and inspection work in Te Puke, 1,500+ documented tyre inspections.
Page © 2026 Tyre Dispatch NZ · Te Puke, New Zealand. Correct as at 1 September 2026. If the manual changes, the checker changes.
General guidance based on published standards and our own workshop data — reliable but hand-compiled and not guaranteed error-free. Spot something wrong? Email email@tyredispatch.co.nz and we'll fix it.