Speed rating chart — every letter to km/h
The letter after your load index — the H in 205/55R16 91H — is the speed the tyre is certified to sustain. Every road letter, drawn to scale. For what the law requires, what the placard means and how to choose, read the full speed rating guide.
Find the letter at the very end of your size marking — after the load index — and look it up below. That speed is what the tyre can sustain, certified by an endurance test. On NZ roads every letter here clears the legal bar; the letter you choose is about the vehicle and the price, not the law.
On this page
Where to find your letter
It is the last character of the size marking on your sidewall, straight after the load index:
Seeing ZR inside the size, or a letter in brackets? Explained below. The number before the letter is the load index — that one has its own chart.
Letter to km/h, drawn to scale
Every road letter from J up. The bar is the certified sustained speed against Y's 300 km/h; the colour is the band it lives in. Letters below J exist (A1–A8, B–G cover 5–90 km/h) but belong to agricultural and specialist equipment, not cars.
H sits out of alphabetical order for historical reasons — it meant "high speed" before the modern sequence existed, and kept its 210 km/h slot when the alphabet filled in around it. U (200) is real but rarely fitted.
What NZ law actually requires
The WOF rule measures your tyre against the speed limit for your vehicle — not your door placard. A tyre fails only if its rating is below the speed limit (or below the vehicle's own top speed, in the rare case that is lower). Every letter on this page passes on NZ roads.
Passes
Q-rated mud-terrains on a ute. A T tyre on a car that came with H. Different letters front and rear — and even side by side on one axle, though we never fit odd pairs.
Fails
A speed rating that has been buffed, painted over or concealed (the marking must stay identifiable). Mixed sizes, carcass types or pattern types on one axle — the rules that actually bite.
The placard letter is the manufacturer's recommendation — a good default, not the law. The full guide has the rule verbatim, the insurance question answered honestly, and the two cases where a lower letter is the right call.
ZR, (Y), ZRF — and load at very high speed
ZR is the pre-1990s way of writing "beyond 240 km/h". On a modern sidewall the real rating is the letter after the load index — 225/40ZR18 92W is a W tyre, interchangeable with a plain R-marked W. (Y) in brackets means certified beyond Y's 300. And in our own catalogue listings, ZRF is a ZR-marked run-flat — the F is the run-flat flag, not a rating.
Load capacity tapers above the reference speed
A tyre's load index is guaranteed up to a reference speed. Push V, W and Y tyres beyond their reference and the standards taper the load they may carry — roughly 3% less per 10 km/h above 210 for V, and 5% less per 10 km/h above 240 for W (to 270) and above 270 for Y (to 300), per the European standards convention published in manufacturer data books. Academic at NZ speeds — but if you tow heavy or track the car, it is the fine print worth knowing. Capacity itself: the load rating chart.
What our shelves actually carry
The 307 tyres in stock and ready to fit as this page was written, grouped by letter. Two things worth noticing: the LT letters (Q–S) are a third of everything we sell, and W — supposedly the exotic letter — is the most common one in the building.
Counts from our live catalogue, 21 August 2026. The letter is not a price: W's median fitted price ($180) is the lowest of any letter we stock, because modern low-profile sizes are W-rated by construction whatever their market position.
This is the quick chart. Want the reasoning?
What the letter certifies, the WOF rule verbatim, mixing, the placard question and our 40-60% rule — the full guide walks through all of it.
(07) 573 9090 · Te Puke, Bay of Plenty · Free North Island delivery
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Taylor Houghton
Manager, Tyre Dispatch · Warehouse Manager, Traction Tyres
Taylor Houghton has spent his working life in the tyre trade, beginning in his father's tyre business at the age of five and handling import containers through his school years. He developed Tyre Dispatch, the retail arm of Traction Tyres, and now manages it alongside the Traction Tyres warehouse in Te Puke, with responsibility for buying and brand selection. He holds no ownership interest in either business.
Both brands the company distributes exclusively in New Zealand, Anchee and Predator, were his selections, each assessed on factory accreditation, compound composition and independent test data rather than name recognition. More than 100,000 Anchee tyres have since been sold here, and both brands hold five star review averages.
The guides, calculators and tools on this site are his own work, as is the workshop dataset behind them, which covers 1,700+ documented tyre inspections and 45,000+ photographs and represents more than a thousand hours, the majority outside business hours. He is the petitioner to Parliament for mandatory tyre performance labelling and minimum wet-grip standards in New Zealand, and appeared in the launch video for Tyrewise, the national tyre stewardship scheme.
Photography, measurements and advice on this site are first-hand; where a figure comes from elsewhere, it is attributed.
Looking for tyre training data? The imagery and structured inspection dataset are available to licence. Contact email@tyredispatch.co.nz.
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.