Winter Tyre Checks: What to Look At Before the Cold Sets In

Quick answer: Winter tyre checks come down to three things: tread depth, pressure and condition.  The legal minimum tread is 1.6mm, but wet grip starts to fall away well before that.  Below about 7°C, summer tyres lose grip, so some owners switch to winter or all-season tyres.  Bartlett Automotive supplies, fits and stores tyres in Huntingdon and Peterborough.

Key Takeaways

• UK law requires at least 1.6mm of tread across the central three-quarters of the tyre, around its whole circumference.
• Driving on an illegal tyre can mean a fine and penalty points.
• Summer tyres can lose steering, acceleration and braking performance below 7°C.
• We recommend checking tyres at least once a month and before long journeys.
• Air contracts as it cools, so tyre pressures tend to drop as temperatures fall, even when nothing is wrong with the tyre.

Quick Navigation

• Tread depth: the legal minimum and the sensible one
• Tyre pressures drop when the temperature does
• Check the condition, not just the numbers
• Summer, all-season or winter tyres?
• Run-flats, low profiles and pressure monitoring
• Frequently Asked Questions
• Useful Links
• What to Do Next

Tread depth: the legal minimum and the sensible one

The law is clear.  Car tyres must have at least 1.6mm of tread across the central three-quarters of the tread, all the way round.  Fall below that and you’re looking at a fine and penalty points for each tyre, which adds up quickly if all four are worn.

The legal minimum isn’t the same as a safe one, though.  Tread is what clears water from under the tyre, and as it wears, wet grip falls away and stopping distances grow.  That matters most in a British winter, when roads are wet far more often than they’re icy.  Many tyre specialists suggest replacing well before 1.6mm, and 3mm is a figure you’ll often hear.

The quickest home check is the 20p test.  Pop a 20p coin into the main grooves.  If you can see the outer band of the coin, the tread may be close to the legal limit and it’s time for a proper look.

Tyre pressures drop when the temperature does

Air contracts as it cools, so a tyre set correctly on a mild September afternoon can be noticeably lower on a frosty December morning.  Under-inflated tyres don’t grip as well, wear unevenly and can make the steering feel vague.

Check pressures when the tyres are cold, ideally before you’ve driven more than a couple of miles and set them to the figures in your handbook or on the sticker inside the driver’s door or fuel filler flap.  Many cars list a different pressure for a full load, so check which applies if you’re heading off at Christmas with a boot full of presents.

Check the condition, not just the numbers

Winter roads are hard on tyres.  Potholes open up after a freeze and a hard knock can leave damage you won’t notice from the driver’s seat.  When you check your tyres, look for:

• Bulges or lumps in the sidewall, often a sign of internal damage from a pothole
• Cuts, cracks or splits in the rubber
• Nails, screws or stones embedded in the tread
• Uneven wear, such as one edge wearing faster than the rest, which can point to an wheel alignment problem

A bulge in particular shouldn’t wait.  Charity, TyreSafe advises that tyres with bumps, cracks or foreign objects embedded in them should be changed immediately.

Summer, all-season or winter tyres?

Many prestige cars are supplied on summer tyres, which are designed for warmer conditions.  According to TyreSafe, their steering, acceleration and braking performance drops once temperatures fall below 7°C, which describes a good chunk of a Cambridgeshire winter.

Winter tyres use a softer compound and a tread pattern designed for cold, wet and icy roads.  All-season tyres sit somewhere in between, trading a little summer sharpness for better cold-weather grip.  Neither is automatically the right answer.  If your car does a short daily run on gritted main roads, good summer tyres with plenty of tread may serve you perfectly well.  If you’re out early on rural roads around the Fens, or covering serious winter mileage, winter or all-season tyres are worth a conversation.

If you do switch, there’s no need to find room in the garage for a second set.  We offer a tyre storage service, so your summer tyres can stay with us until spring.  There’s a small storage charge, plus labour each time the tyres are swapped over.

Run-flats, low profiles and pressure monitoring

Many BMW and MINI models are fitted with run-flat tyres, and plenty of prestige cars run low-profile tyres on large alloys.  Both need care when they’re fitted.  Low-profile tyres leave very little rubber between the rim and the road, so kerbs and potholes are more likely to damage the wheel and fitting them properly takes the right equipment.

We supply and fit run-flat, low-profile and winter tyres, and we’ll talk you through the options that suit your car and the way you drive.

Most modern cars also have a tyre pressure monitoring system (TPMS).  If the warning light comes on as the weather turns cold, it may simply be pressures dropping with the temperature, but don’t assume.  Check all four tyres and if the light stays on after inflating them correctly, get it looked at.

Frequently Asked Questions

What is the legal tyre tread depth in the UK?

The legal minimum for cars is 1.6mm across the central three-quarters of the tread, around the whole circumference.  Driving on tyres below that can lead to a fine of up to £2,500 and three penalty points per tyre.

Do I need winter tyres in the UK?

There’s no legal requirement to fit winter tyres in the UK.  They make the most difference if you regularly drive in temperatures below 7°C, on rural or untreated roads or early in the morning.  For many drivers, all-season tyres or good summer tyres with healthy tread are a reasonable compromise.

Why does my tyre pressure warning light come on in cold weather?

Air inside the tyre contracts as it cools, so pressures can drop enough overnight to trigger the warning.  Check and adjust all four tyres to your handbook figures while they’re cold.  If the light comes back on, there could be a slow puncture or a sensor fault.

How often should I check my tyres in winter?

It is recommended to check tread, pressure and condition at least once a month and before any long journey.  In winter, a quick look after hitting a pothole is worth doing too.

Can you store my summer tyres over the winter?

Yes.  Bartlett Automotive offers a tyre storage service.  There’s a small storage charge, plus a labour charge each time the tyres are swapped over.

Useful Links

• TyreSafe: the UK’s tyre safety charity
• The Highway Code: Driving in adverse weather conditions (rules 226 to 237)
• UK: Check the MOT history of a vehicle (including tyre advisories)
• Met Office: UK weather warnings
• Bartlett Automotive: The truth about winter tyres
• Bartlett Automotive: Tyre tread safety

What to Do Next

If your tyres are getting close to 3mm, have taken a hit from a pothole or you’re weighing up winter tyres, have a chat with us before the cold weather properly arrives.  We’ll check tread, pressures and condition, explain your options honestly and fit or store tyres to suit.  Find out more about our tyre fitting and storage.

Call our Huntingdon workshop (BMW, MINI and Porsche) on 01480 459 771 or our Peterborough workshop (BMW, MINI and Mercedes-Benz) on 01733 852 955.