A British winter does not often bring Alpine conditions, but it does bring the specific mix that catches cars out: cold starts, wet leaves, black ice on bridges, salt, and the first dark commute of the year. The list below is short on purpose. Do these and the rest of the season looks after itself.
Tyres: tread, pressure, and age
The UK legal minimum tread depth for cars is 1.6 mm across the central three quarters of the tyre, around the whole circumference. Tyre safety information and the legal minimum are set out in the Highway Code and on the gov.uk guidance pages linked below. In winter wet, 3 mm is a far safer floor; below 3 mm, braking distances climb sharply on standing water.
Pressures drop by about 1 psi for every 5 °C of temperature fall. A car set in October to the door-placard figure will often be 2-3 psi low by December. Check cold, at a forecourt where you trust the gauge, or buy a £10 pencil gauge.
Tyre age matters too. Look at the DOT code on the sidewall: four digits for week and year. A 2019 tyre with 7 mm of tread may feel fine but will have hardened compound; cold-weather grip will be worse than a newer tyre with 5 mm.
Battery: the first cold week is the test
Most car batteries last four to six years. They almost always fail in the first properly cold week of the year, not in July. If you had a slow crank last winter and did nothing about it, this winter it will leave you stranded.
Two things buy you another season on a tired battery:
- A twenty-minute drive at least once a week; short trips in the dark with the heater, heated seats and lights on are a net drain.
- Making sure you are not leaving a USB device, dashcam or aftermarket alarm pulling current from the auxiliary socket when the car is parked.
If the car has not been driven for a fortnight, a smart trickle charger on the battery (plugged into a garage socket, not a cigarette lighter) will see it through.
Screenwash
Summer-only screenwash freezes in the reservoir and the lines. Buy a concentrate rated to at least -15 °C, dilute to the colder side of the label's recommendation, and use it. Plain water; including water with "a splash" of summer wash; will crack the reservoir if the car sits out in a hard frost.
Replace wipers that scrape or leave half-moons. A new pair is £25 for the car; a cracked windscreen from a stone chip spreading on a wiped-dry pass is £75-£300.
Visibility: lights and glass
Walk round with the lights on. A blown rear bulb is the easiest reason to be stopped by a traffic officer in November. For a worked example, see our roadside stops article.
Clean the inside of the windscreen with a microfibre and a drop of washing-up liquid in warm water. The oily film that builds up from heater outlets and off-gassing plastics is invisible in summer and catches every headlight of oncoming traffic in winter.
If your headlight lenses are hazy or yellowed, a plastic lens restoration kit is £15 and an hour of work. On an older car this is the single biggest night-driving upgrade you can do.
Coolant and the heater
If the cabin is slow to warm up, or you run the heater on full and get lukewarm air, two usual causes: a stuck thermostat (cheap to fix) or a partly blocked heater matrix (not cheap). Both are worth sorting before Christmas, not after.
Check the coolant strength at a garage if you do not know when it was last changed. UK antifreeze should be good to about -35 °C, which the UK will not reach, but weak coolant also stops being an effective corrosion inhibitor, and that is when heater matrices start to leak.
In the car itself
You do not need a full winter kit for a school-run car. You do want:
- A proper ice scraper, not a credit card.
- A can of de-icer kept inside the house (a can in the car is frozen when you need it).
- A warm layer and a pair of gloves on the back seat.
- A phone charger that works from the car's socket, and a note of your breakdown number saved offline.
- A small torch, or the one in your phone with the battery actually charged.
For long trips across moorland or snow-prone routes, add a flask, a snack and a blanket. The recovery van exists but it is not always nearby.
Three-minute pre-drive checkWalk round the car: lights front and back, tyres (any one obviously soft), ice on the roof (knock it off; it will slide onto your windscreen at the first brake). Start, wipe inside and out, demist, then go. Skipping this is where most winter drivers come unstuck.
If you skidLift off the accelerator, do not stamp on the brakes, steer gently into the direction of the skid. Most modern cars have ABS and stability control, which do the hard part; your job is to not fight them.
One thing you can skip
You do not need winter tyres in most of the UK to get through most winters. A set of all-season tyres to the right rating is a reasonable middle ground, especially if you live on a hill or on a single-track road the council does not grit. If you do fit true winter tyres, keep the summers on separate rims so you can swap each autumn and spring without re-mounting.
Related: our MOT article covers tyre, light and wiper checks in more detail, and the used-car guide runs through the cold-start test that will save you a January surprise.
Primary sources: gov.uk's tyre safety and Highway Code pages, the AA's cold-weather advice at theaa.com, and the RAC's winter checklist at rac.co.uk.