Cold weather, shorter days, and wet roads make winter the most demanding season for your car and its components. A few straightforward checks in October or November can prevent a breakdown, an MOT failure, or a dangerous situation on a frosty morning. This checklist covers everything UK drivers should do before the temperature drops.
Battery
The battery is the most common cause of winter breakdowns in the UK. Cold temperatures reduce a battery's ability to deliver the high current needed to start the engine, and a battery that is borderline during summer will often fail completely on a cold January morning.
If your battery is more than 3–4 years old, have it tested before winter. Most garages and motor factors will carry out a free or low-cost battery test. A healthy battery should hold 12.6 V at rest and deliver over 10 V during cranking. If it fails this test, replace it before the cold weather arrives — a new battery costs £60–£150 fitted at most garages, far less than a breakdown call-out.
Tyres
Tyre tread becomes more critical in winter: wet and cold roads increase stopping distances significantly, and a tyre with marginal tread at 2 mm may behave dangerously in winter conditions even though it is technically legal. Consider replacing tyres that are below 3 mm before winter.
Also check tyre pressures monthly throughout winter. Cold air is denser, and tyre pressure drops by approximately 1 PSI for every 10°C drop in temperature. Under-inflated tyres handle poorly in wet and icy conditions. Your recommended tyre pressures are in the vehicle handbook or on a sticker inside the driver's door frame.
Winter tyres (rated for below 7°C) are increasingly popular in the UK but not legal requirements. They offer significant grip improvements in cold, wet conditions but are not strictly necessary for most UK drivers unless you live in a rural area prone to snow and ice.
Engine Coolant (Antifreeze)
Engine coolant serves two purposes: it prevents the water in your cooling system from freezing in winter and from boiling in summer. Most modern cars use a pre-mixed coolant that should be changed every 2–5 years depending on the manufacturer's recommendation.
The key check for winter is the antifreeze concentration. The mixture should protect down to at least -25°C for UK winter conditions (most recommend -35°C or lower in colder regions). A coolant tester costs a few pounds and can check the protection level in seconds. If the protection level is inadequate, the cooling system needs draining and refilling — a job best left to a garage.
Do not simply top up with water if the coolant level is low. This dilutes the antifreeze concentration and reduces freeze protection.
Lights, Screenwash, and Wipers
Winter brings shorter days and reduced visibility, making working lights more important — and an MOT failure risk if they are not maintained. Walk around your car on a dark evening and check every light: headlights (dipped and full beam), brake lights, indicators, fog lights, and reversing lights. Replace any failed bulbs before winter.
Screenwash is one of the most commonly neglected fluid checks. Plain water in the washer reservoir will freeze solid overnight in sub-zero temperatures, leaving you without a functioning screen wash on a frosty morning — a dangerous situation on a motorway. Use a concentrated screenwash fluid that protects to at least -15°C in winter.
Inspect your wiper blades for splitting or streaking. Winter wiper blades are available that resist ice build-up, though standard blades in good condition are adequate for most UK winters. Do not use your wipers on a frozen windscreen — the rubber tears and the motor can be overloaded.