What is the legal minimum tread depth in the UK?

1.6mm across the central three-quarters of the tread, around the entire circumference, for most cars. Many garages recommend replacing closer to 3mm for wet grip.

Do TPMS sensors replace monthly checks?

No. Tyre pressure monitoring systems warn of a significant drop, but they will not catch gradual under-inflation as reliably as a monthly gauge check.

Should front and rear pressures match?

Often they differ. Follow the vehicle sticker. SUVs and estates frequently run higher rear pressures when loaded.

Can low pressure fail an MOT?

Severely under-inflated or damaged tyres can fail. Uneven wear from chronic wrong pressures also shortens tyre life and can affect braking.

Practical car tool

Tyre pressure checker

Record the cold tyre pressures recommended for your car and convert between PSI and bar. Always treat the sticker in the door shut, fuel flap or handbook as the legal source of truth — not the maximum moulded into the tyre sidewall.

Front pressure (PSI)Rear pressure (PSI)

I am carrying a full load

Your reminder

32 PSI front · 30 PSI rear

≈ 2.21 bar front · 2.07 bar rear

Check pressures when tyres are cold, at least monthly and before long trips.

How to set tyre pressures correctly

Check pressures when the tyres are cold — before a long drive, or at least three hours after the last trip. Warm tyres read higher and can trick you into under-inflating.

Most UK cars list two sets of figures: normal load and full load (passengers and luggage). The loaded setting is usually a few PSI higher, especially on the rear axle of hatchbacks and estates.

The large number on the tyre sidewall is the maximum pressure the tyre can safely hold, not the recommended pressure for your car. Using it as a daily setting can make the ride harsh and wear the centre of the tread.

Common pressure mistakes

Using garage forecourt gauges without checking cold figures

Forecourt compressors are fine if calibrated, but measure after a motorway run and you will over-correct. Note your cold sticker pressures first, then top up.

Ignoring a slow puncture because the car “still drives fine”

A tyre that needs air every few days is not normal. Inspect for nails, rim damage or a leaking valve before the sidewall is destroyed.

Mixing PSI and bar on the same car

Stickers may show both. 32 PSI is about 2.2 bar. This tool converts so you can match whatever your gauge displays.

Frequently asked questions

What is the legal minimum tread depth in the UK?: 1.6mm across the central three-quarters of the tread, around the entire circumference, for most cars. Many garages recommend replacing closer to 3mm for wet grip.
Do TPMS sensors replace monthly checks?: No. Tyre pressure monitoring systems warn of a significant drop, but they will not catch gradual under-inflation as reliably as a monthly gauge check.
Should front and rear pressures match?: Often they differ. Follow the vehicle sticker. SUVs and estates frequently run higher rear pressures when loaded.
Can low pressure fail an MOT?: Severely under-inflated or damaged tyres can fail. Uneven wear from chronic wrong pressures also shortens tyre life and can affect braking.

Related tools and guides

MotorTools calculators give planning estimates only. Confirm figures against GOV.UK, your V5C, handbook or a qualified garage before buying, renewing tax or carrying out work.