How to prepare your car for winter driving

Check your coolant before the first frost

Antifreeze is the quiet hero of winter motoring, and it is easy to forget about until a cold snap exposes a weak mixture. The coolant in your system should be a roughly equal mix of water and antifreeze, which protects the engine down to around -37°C and also prevents corrosion and overheating in summer. Pop the bonnet when the engine is completely cold, find the coolant reservoir, and check the level sits between the MIN and MAX marks. If it is low, top it up with the correct ready-mixed coolant for your car rather than neat water.

Topping up with plain water is fine in an emergency, but it dilutes the mixture and raises the temperature at which it freezes. If you find yourself adding coolant regularly, that points to a leak somewhere, and it is worth having it looked at before the really cold weather arrives. A frozen coolant system can crack the engine block, which turns a ten-pound bottle of antifreeze into a very expensive repair.

Give the battery a fighting chance

Cold weather is brutal on batteries. The chemical reactions inside slow down, so a battery that has been quietly fading all autumn can suddenly refuse to start the engine on a frosty morning. Meanwhile, the engine itself is harder to turn over because the oil is thicker, so the battery is being asked to work harder at exactly the moment it has less to give.

Most batteries last around four to five years, so if yours is approaching that age, treat it with suspicion. A healthy, fully charged battery should rest at around 12.6 volts; anything near 12.0 volts or below suggests it is struggling. Listen to the engine as you start it, too. Slow, laboured cranking is a warning sign. Check the terminals for white or green crusty deposits, clean them carefully, and smear a little petroleum jelly on top to keep corrosion at bay.

If you mostly do short journeys, your battery never really gets a full charge, because the starter motor takes out more than the alternator puts back. A trickle charger or battery conditioner used once a fortnight over winter is a genuinely worthwhile investment for low-mileage drivers.

Tyres: your only contact with the road

Tyres deserve more attention in winter than at any other time of year. The legal minimum tread depth in the UK is 1.6mm, but for winter driving you want at least 3mm across the whole width of every tyre, including the spare. Grip in wet and icy conditions falls away sharply once you get below that.

Check your pressures when the tyres are cold, because cold air contracts. As a rough rule, pressures drop by around 1 psi for every 5°C the temperature falls, so a tyre that was spot on in September may be noticeably under-inflated by December. Under-inflated tyres wear faster, use more fuel and reduce your grip.

If you live somewhere rural or regularly drive on untreated roads, proper winter tyres are a revelation. Their rubber stays flexible below 7°C, which is where summer tyres start to harden and lose grip. Good all-season tyres are a sensible compromise for most drivers who do not want the hassle of swapping wheels twice a year.

Sort out visibility: screenwash, wipers and lights

Use a proper concentrated screenwash at winter strength rather than diluting it down or, worse, using washing-up liquid, which smears and can damage paintwork. Water alone will freeze in the jets and on the windscreen, leaving you blinded by spray from the car in front.

Replace wiper blades if they are smearing or juddering, and give the inside of the windscreen a clean too, as a greasy film makes misting far worse. Walk around the car and check every bulb: headlights, brake lights, indicators, reverse, fog and the number plate lights. Give the lenses a wipe while you are there, because a film of winter grime can cut their output dramatically.

Pack a winter kit in the boot

A little preparation here can turn a miserable hour at the roadside into a minor inconvenience. Store these in the boot and leave them there until spring:

• A sturdy ice scraper and a can of de-icer
• A warm blanket, plus gloves, a hat and spare boots
• A torch, ideally a wind-up or one with spare batteries
• A high-visibility vest for each occupant
• Jump leads, a tow rope and a small shovel
• A bag of grit, sand or cat litter for extra traction
• A fully charged phone power bank and a charging cable
• Bottled water and a few non-perishable snacks
• A basic first aid kit and any essential medication
• A warning triangle and a spare set of bulbs

Build some cold-weather habits

Before you set off, clear every window, both mirrors, all lights and the number plate, and brush snow off the roof. It is a legal requirement to have a full view of the road, and snow sliding off your roof onto the windscreen of the car behind is genuinely dangerous. Never leave the engine running unattended to warm up, as it is an invitation to thieves and your insurer may take a dim view.

Once moving, drive gently for the first few miles and allow extra time for every journey. Stopping distances on ice can be up to ten times longer than on a dry road, so leave a generous gap and brake softly and early. Use gentle inputs on the steering, accelerator and brakes, and pull away in a higher gear than usual to reduce wheelspin. On hills, keep momentum steady and leave plenty of room ahead so you are not forced to stop. If you do get stuck, resist the urge to spin the wheels; clear the snow from around the tyres, add grit, and ease the car out steadily.