Summer and winter tyres are engineered for opposite temperatures. Summer tyres grip best in warm conditions above about 7°C; winter tyres are built to stay flexible and bite in the cold. Using the wrong one out of season costs you grip and lengthens your stopping distance, exactly when you can least afford it. The 7°C crossover is the rule of thumb to remember.
Summer tyres
Summer tyres are the default fit on most UK cars and are optimised for the warmer half of the year:
- A harder compound that stays stable in heat for sharp dry and wet grip.
- Tread designed to clear water and resist aquaplaning in warmer rain.
- Lower rolling resistance, so slightly better economy in summer.
- They harden and lose grip once it gets properly cold.
Winter tyres
Winter tyres aren't just for snow, they're for cold. Below about 7°C they outperform summer tyres even on dry roads:
- A softer compound that stays flexible below 7°C.
- Lots of fine sipes that grip snow, ice and slush.
- Noticeably shorter cold-weather braking distances.
- They wear faster and feel vague if used through summer heat.
The 7°C rule
The single most useful thing to know is the 7°C crossover, highlighted by TyreSafe. Above that temperature, summer tyres grip better and last longer. Below it, the summer compound stiffens and a winter tyre's softer compound and siping take over, giving shorter braking and more confident cornering even on dry, frosty roads. It's a temperature rule, not a snow rule, which is why winter tyres earn their keep on plenty of cold but clear UK days, not just when it snows.
Which should you run?
If you swap sets, run summer tyres from spring to autumn and winter tyres through the cold months, using that 7°C average as your switch point. If you'd rather not swap twice a year, all-season tyres give you a year-round compromise that suits much of the UK's mild climate. For most drivers in milder areas, all-season tyres are the practical middle ground; for those facing real cold, snow or hills, a dedicated winter set is worth the swap. One thing to avoid is running winter tyres into the summer to "use them up": the soft compound wears fast in the heat and the handling goes vague, so you lose money and grip at once. Whichever you choose, fit them as a full matched set of four, because mixing summer and winter tyres across the car upsets the balance of grip, especially in an emergency stop.
Summer vs winter tyres at a glance
The differences come down to compound, tread design and the temperature each is built for. Everything else on this page follows from the table below.
| Summer tyre | Winter tyre | All-season tyre | |
|---|---|---|---|
| Compound | Firmer, stable in heat | Softer, stays flexible in cold | In between |
| Best temperature | Above about 7°C | Below about 7°C | Compromise across both |
| Tread | Fewer, wider grooves; large blocks | Deep grooves, many sipes | Moderate siping |
| Warm wet braking | Best | Longer | Close to summer |
| Cold and icy braking | Longest | Best | Much better than summer |
| Snow and slush | Poor | Best | Good |
| Wear in summer heat | Normal | Fast | Slightly faster than summer |
| Sidewall marking | None specific | 3PMSF snowflake | Usually 3PMSF |
The row that surprises people is warm wet braking. A winter tyre is not a rain tyre; in warm conditions its soft compound squirms and it stops less well than a summer tyre on the same wet road. That is why running winter tyres all year is a poor idea, not just a slightly wasteful one.
The EU tyre label shows wet grip graded A to E and helps compare tyres of the same type, but it is measured in warm conditions, so it will not tell you how a winter tyre performs in the cold, see the EU tyre label explained.
How to tell which tyres you have
Look on the sidewall for a three-peak mountain with a snowflake inside it. That is the 3PMSF symbol, and it means the tyre has passed a standardised snow traction test. Without it, treat the tyre as a summer tyre in snow, whatever it says on the box.
- 3PMSF (three-peak mountain snowflake): a certified winter or all-season tyre. This is the marking that matters.
- M+S alone: "mud and snow" is a manufacturer's description with no test behind it. Plenty of summer-compound SUV tyres carry it. Do not treat it as a winter tyre.
- Nothing: a summer tyre.
Our guide to the three-peak snowflake symbol explains the test.
Two other clues help. Winter tyres have a visibly busier tread, with hundreds of fine slits across each block, and the rubber feels noticeably softer when you press a thumbnail into it. If you have bought a used car and are not sure what is fitted, check all four, because previous owners sometimes run odd pairs.
Mixing types across the car is legal but a bad idea: two winter tyres on the front and two summer tyres on the rear gives the car far more grip at one end than the other, which is exactly what makes a skid unpredictable. Fit all four the same, see replacing tyres in pairs.
Two sets of wheels, or swap the tyres?
If you are going to run a winter set every year, a second set of wheels pays for itself quickly and is kinder to the tyres.
Swapping tyres on and off the same rims twice a year means all four tyres are removed, refitted and rebalanced at every change, and each of those is a cost and a small amount of wear at the bead.
| Second set of wheels | Swap tyres on one set | |
|---|---|---|
| Upfront cost | Higher: wheels plus tyres | Lower: tyres only |
| Each seasonal change | A wheel swap, quick and cheap | Four tyres refitted and rebalanced |
| Tyre wear from fitting | None | Some, at the bead, each time |
| TPMS | Needs sensors in the second set | Uses the existing sensors |
| Storage | Four complete wheels, stackable | Four loose tyres, stored upright |
Steel wheels are the usual choice for a winter set: cheaper, and they shrug off salt and kerbs that would ruin an alloy. Check the size, offset and bolt pattern match your car, and that the smaller tyre size, if you go down a rim size, is one the manufacturer approves.
TPMS is the hidden cost. If your car has sensors in the wheels, the second set needs its own, and the car has to learn them at each swap. Whichever route you take, store the off-season set clean, dry and out of sunlight, see seasonal tyre storage guide.
Winter tyres, the law and your insurance
There is no UK law requiring winter tyres, and no law against using summer tyres in snow. The legal requirements are the same all year: at least 1.6mm of tread across the central three-quarters, no cuts or bulges, and the correct size and construction for the car, as set out on GOV.UK.
That said, a tyre that is legal is not necessarily adequate. If you have a collision on summer tyres in the snow, nobody will prosecute you for the tyres, but you will have had a longer stopping distance than you needed.
Insurance is simpler than people fear. Fitting winter tyres of the correct size and rating is routine maintenance rather than a modification, and many UK insurers say so in their policy documents. If you are unsure, a quick call to confirm costs nothing.
The one thing to avoid is fitting a lower speed rating than your car specifies without checking; some winter tyres carry a lower rating, and the handbook or the insurer may have a view on it.
Driving abroad is different. Several European countries require winter tyres, or 3PMSF-marked tyres, in winter conditions or on signed roads, and some require snow chains to be carried. Check the rules for each country on your route before you go; the requirements change and the fines are real.
For the cost side of the decision, see are winter tyres worth it in the UK, which weighs the outlay against the number of cold days most of us actually drive.
The swap is easy with us
We can supply summer, winter and all-season tyres and fit or swap them at your home or work, from our base at Brent Cross, NW2. Call and we will tell you whether we can reach you and give you an arrival time.
