What should I verify before using this information?

Use TireFitLab values as a sizing reference, then verify the vehicle handbook, tire placard, rim compatibility, load rating, and physical clearance before fitting.

MOT and roadworthiness tyre requirements

What do inspectors check on tyres during an MOT?

MOT testers and equivalent EU roadworthiness inspectors check: tread depth (minimum 1.6 mm across the central three-quarters of the tread width, around the full circumference), sidewall condition (no bulges, cuts to the cords, or deformation), correct inflation (TPMS warning light must be off), consistent tyre type on each axle (mixing crossply and radial on the same axle is an immediate fail), speed and load rating not below the vehicle specification, and no re-grooved tyres unless marked RG on the sidewall. A single tyre with any one of these faults is an MOT failure.

MOT testers and equivalent EU roadworthiness inspectors check: tread depth (minimum 1.6 mm across the central three-quarters of the tread width, around the full circumference), sidewall condition (no bulges, cuts to the cords, or deformation), correct inflation (TPMS warning light must be off), consistent tyre type on each axle (mixing crossply and radial on the same axle is an immediate fail), speed and load rating not below the vehicle specification, and no re-grooved tyres unless marked RG on the sidewall.
A single tyre with any one of these faults is an MOT failure.

FAQ

What do inspectors check on tyres during an MOT?: MOT testers and equivalent EU roadworthiness inspectors check: tread depth (minimum 1.6 mm across the central three-quarters of the tread width, around the full circumference), sidewall condition (no bulges, cuts to the cords, or deformation), correct inflation (TPMS warning light must be off), consistent tyre type on each axle (mixing crossply and radial on the same axle is an immediate fail), speed and load rating not below the vehicle specification, and no re-grooved tyres unless marked RG on the sidewall. A single tyre with any one of these faults is an MOT failure.
What should I verify before using this information?: Use TireFitLab values as a sizing reference, then verify the vehicle handbook, tire placard, rim compatibility, load rating, and physical clearance before fitting.

What inspectors check: full breakdown

Check	Standard	Fail criteria	Notes
Tread depth	Minimum 1.6 mm across the central ¾ of the tread width, around the full circumference. This applies to the main groove depth — not the tread wear indicator bars.	Any part of the central three-quarters of any tyre below 1.6 mm = immediate fail. Advisory issued at 2–3 mm depending on tester discretion.	Wet-market minimum is 3 mm in some regions (Austria, Germany advisory). 1.6 mm is the legal floor, not a safe operational minimum.
Sidewall condition	No bulges, lumps, or deformation. No cuts, tears, or abrasion exposing the cords (ply structure).	Any cord-exposing cut or bulge = fail. Superficial surface cracking (Grade 1–2) is typically advisory, not fail. Grade 3–4 cracking that exposes cords = fail.	A bulge indicates internal structural damage. Even a small bulge is dangerous and is an immediate fail — the tyre will not be repaired, it must be replaced.
Inflation / TPMS	TPMS warning light must not be illuminated. Tyre must appear properly inflated — obvious under-inflation or over-inflation is noted.	TPMS warning light on = advisory or fail depending on the system fault. A flat or visibly deflated tyre = fail.	The MOT does not use a pressure gauge. Testers rely on visual inspection and TPMS. Inflate tyres to specification before presenting for test.
Tyre type consistency per axle	Both tyres on the same axle must be the same construction type. Crossply (bias) and radial tyres must not be mixed on the same axle.	One crossply and one radial on the same axle = immediate fail.	Mixing brands, tread patterns, or compound types on the same axle is legal in the UK and most EU countries — only construction type (crossply vs radial) is regulated per axle.
Speed and load rating	Tyre speed rating must meet or exceed the vehicle's type-approval speed rating. Load index must meet or exceed the vehicle specification.	A tyre with a lower speed rating than the vehicle type-approval specifies = fail. A tyre with a lower load index than required = fail.	Winter tyre exception: lower speed rating permitted in markets that allow it if vehicle top speed is restricted to tyre rating and a speed sticker is displayed (Germany, Austria, some others).
Re-grooved tyres	Tyres must not be re-grooved unless they are specifically approved for re-grooving, indicated by the RG marking on the tyre sidewall.	Any re-grooved tyre without the RG marking = fail.	Re-grooving (cutting new grooves into a worn tread using a heated blade) is legal only on tyres manufactured with a dedicated sub-tread rubber layer for this purpose. Most passenger car tyres are not RG-approved.
Spare tyre	UK MOT: spare tyre is not inspected. EU roadworthiness tests: spare also not typically inspected in most member states.	The spare tyre is generally not part of the roadworthiness test.	Even though the spare is not tested, a failed spare leaves you without a recovery option. Check spare tyre age and pressure regularly.

Tread depth in detail

The 1.6 mm legal minimum applies to the central three-quarters of the tread width, around the full circumference of the tyre. This means:

If the shoulder edges of the tread are worn below 1.6 mm but the central portion is above the limit, the tyre may technically pass — though this indicates misalignment or pressure issues.
If any section of the central three-quarters drops below 1.6 mm anywhere around the circumference, the tyre fails regardless of how much tread remains elsewhere.
Tread wear indicator (TWI) bars are moulded at exactly 1.6 mm depth. When the surface of the tread is flush with any TWI bar, the tyre is at the legal limit. For the full TWI guide, see our Tyre wear indicators guide.

1.6 mm is not safe — it is the legal floor. At 1.6 mm on a wet road at 80 km/h, stopping distance is approximately 60 m. At 3 mm it is approximately 35 m. Major tyre associations (ETRTO, TyreSafe UK, ADAC) recommend replacing tyres at 3 mm in wet conditions. For the full wet braking impact table, see our Tire tread depth guide.

Roadworthiness test requirements by country

Country / Test	Frequency	Tread min	Axle mixing rule	Speed rating	TPMS
United Kingdom — MOT	Annual from 3rd year	1.6 mm	Crossply and radial must not be mixed on same axle	Must meet vehicle type-approval minimum	TPMS light on = advisory or fail
Germany — HU (TÜV/DEKRA/GTÜ)	Every 2 years (first test 3 years after first registration)	1.6 mm (3 mm recommended by ADAC)	Crossply and radial must not be mixed on same axle	Must match vehicle specification (StVZO §36)	RDKS warning must be off
France — Contrôle Technique	Every 2 years from 4th year	1.6 mm	No crossply/radial mixing on same axle	Confirmed for vehicle type	TPMS warning = défaut majeur (major fault)
Spain — ITV	First test 4 years, then every 2 years, annual after 10 years	1.6 mm	No crossply/radial mixing on same axle	Must meet vehicle specification	TPMS fault = defecto
Italy — Revisione	First at 4 years, then every 2 years	1.6 mm	No crossply/radial mixing on same axle	Must meet vehicle specification	TPMS fault recorded
Poland — Przegląd techniczny	Every year	1.6 mm	No crossply/radial mixing on same axle	Must meet vehicle specification	TPMS fault recorded
Netherlands — APK	Annual from 4th year	1.6 mm	No crossply/radial mixing on same axle	Must meet vehicle specification	TPMS warning = gebrek

Tyre mixing: what is and is not allowed

A common misconception is that all tyre mixing fails a roadworthiness test. The actual rule is narrower:

Crossply vs. radial on the same axle: prohibited — this is the structural construction type, identified by the presence or absence of an "R" in the tyre size designation. A 205/55R16 is radial; a 205/55-16 (no R) is crossply (now extremely rare on passenger vehicles).
Different brands on same axle: legal in the UK and all major EU markets. Not recommended by tyre manufacturers (handling asymmetry), but not a test failure.
Different tread patterns on same axle: legal — mixing a winter and summer tyre pattern on the same axle is legal in the UK, though it is dangerous and strongly discouraged.
Different compounds on same axle (e.g. summer + all-season): legal at the roadworthiness test. The inspector does not test compound chemistry.
Lower speed rating on rear than front: a grey area — prohibited by most tyre manufacturers' guidance but not always a test failure. Consult your inspection authority.

TPMS and roadworthiness tests

Since 2014, all new cars sold in the EU must be fitted with TPMS. Since 2012 in the USA (FMVSS 138). Since 2015 in the UK (as part of EU adoption). Roadworthiness tests increasingly flag a TPMS warning light as a defect:

UK MOT (from 2023): A TPMS warning light is classified as a "major defect" — this is a fail, not merely an advisory. The vehicle cannot be issued an MOT certificate with the light on.
EU member states: Treatment varies. Most classify a TPMS fault as a "major defect" under EU Roadworthiness Directive 2014/45/EU. Present the vehicle with all tyres inflated to specification — most TPMS systems reset within a few minutes of driving.

If the TPMS light remains on after inflating to the correct pressure and driving for a few km, a sensor may be faulty or battery depleted. Sensors typically last 5–10 years. For full TPMS guidance, see our TPMS guide.

Most common tyre-related test failures

Failure reason	Frequency	How to prevent
Tread below 1.6 mm	Most common tyre failure reason	Check monthly with tread depth gauge. Replace when below 3 mm — 1.6 mm is the legal limit, not a safety recommendation.
Sidewall bulge or cord exposure	Common — often caused by pothole impact	Inspect sidewalls monthly. After any significant pothole or kerb strike, inspect both the sidewall and the inner liner immediately. A bulge cannot be repaired — replace the tyre.
TPMS warning light on	Increasingly common as TPMS becomes mandatory	Check tyre pressures before presenting for test. Inflate to specification and drive a few km so the TPMS system recalibrates. If light remains on, check for a faulty sensor.
Speed rating below vehicle specification	Less common but increasing with seasonal tyre switching	When buying winter or seasonal tyres, verify the speed rating is at or above your vehicle's type-approval minimum. Check the door sticker or owner's manual.
Re-grooved tyre without RG marking	Rare for passenger cars	Never re-groove passenger car tyres unless specifically marked RG. No benefit for passenger car usage.

Pre-test tyre checklist

Action	Tool needed	Pass threshold
Check tread depth on all four tyres	Tread depth gauge or 20p coin (UK)	Replace if below 3 mm — 1.6 mm is the legal limit, not a safe minimum
Inspect all sidewalls for bulges, cuts, or cord exposure	Visual inspection in good light	Any bulge or cord exposure = replace immediately before presenting for test
Inflate all tyres to OEM specification	Calibrated tyre pressure gauge	Use cold pressure specification from door sticker or owner's manual
Verify TPMS warning light is off	Dashboard check	If lit, inflate to correct pressure, drive 5 km, check again. Persistent warning = sensor fault to fix
Confirm speed and load rating on all four tyres match or exceed OEM	Read tyre sidewall service description	Speed symbol and load index must be at or above the vehicle door sticker specification
Check that all four tyres are radial (not crossply)	Sidewall marking — radial shows "R" in size string (e.g. 205/55R16)	Crossply tyres have no "R" — they show "B" (belted bias) or no letter

Can a tyre be repaired to pass?

Puncture repairs are legal and safe when carried out correctly according to BSAU 159g (UK) or ETRTO standards. A professionally repaired tyre using an internal mushroom patch on the tread area can pass a roadworthiness test. However:

Sidewall repairs are not permitted — a sidewall puncture requires tyre replacement.
Plugs alone (without internal patch) are not considered a permanent repair and should be followed by proper mushroom-patch repair or tyre replacement.
Run-flat tyres that have been driven in run-flat mode (zero pressure for any distance) must be inspected and in most cases replaced — internal damage is not visible externally.

For the full puncture repair guide, see our Tyre puncture repair guide.

More tools

Last reviewed: 2026-06-22

Last reviewed: 2026-06-28

What changed

Reviewed deterministic geometry, load/speed references, sitemap inclusion and localized page shell.