Winter car checklist: what to check before the cold sets in.

There is a particular kind of cold morning when the windscreen is frosted, the heater is blowing cold and the car turns over slowly or not at all. It is rarely the cold alone. Cold finds the weak point: a battery that was marginal in September, tyres with less tread than you thought, wipers that smear. This checklist covers the things worth looking at before the weather turns, roughly in order of how often they catch people out.

Battery

Cold slows the chemical reaction inside a battery, so it delivers less power just when the engine needs more to turn over (cold oil is thicker). Add heated screens, lights and the heater fan, and a weak battery that coped all summer gives up.

• Age is a clue. Many car batteries last around five years, plenty fail sooner, and a battery that is three or four years old is worth testing before winter.
• Slow cranking, dim lights at idle, and a dashboard that flickers on starting are all warnings.
• Short journeys do not give the alternator time to recharge the battery after starting, which is hard on it in winter.
• A proper test uses a battery tester that measures its condition under load, not just a voltage reading.

Cars with stop-start systems often use a different type of battery (AGM or EFB) and need the correct replacement, so do not assume any battery will do.

Tyres

Tyres are the only part of the car in contact with the road, and in cold, wet or icy conditions they matter even more.

• Tread depth. The legal minimum in the UK is 1.6mm across the central three quarters of the tread. Many tyre makers and motoring organisations suggest considering replacement before they reach about 3mm, because wet and cold grip fall away well before the legal limit.
• Pressure. Pressure drops as temperature falls. Check them cold, against the figures in your handbook or the sticker in the door frame or fuel flap, not the maximum printed on the sidewall.
• Condition. Look for cuts, bulges, cracking and uneven wear. Uneven wear can point to alignment or suspension problems.
• Spare or repair kit. If your car has a spare, check it is inflated. If it has a sealant kit, check it is in date.

All-season and winter tyres are options for some drivers, but they are a choice to discuss for your car and use, not a necessity.

Coolant and antifreeze

Coolant is a mix of antifreeze and water. The antifreeze protects the engine from freezing and the cooling system from corrosion. If the mix is too weak, the coolant can freeze, and ice can do serious damage.

• Check the level in the expansion tank with the engine cold. It should sit between the MIN and MAX marks.
• Never open the cap on a hot engine.
• If the level keeps dropping, there is a leak or another fault that needs finding.
• Coolant should be changed at the interval in your handbook, as its protective additives wear out. Use the specification the manufacturer calls for; mixing different types can cause problems.

If you do not know when the coolant was last changed, a quick strength test is a sensible check.

Wipers and screenwash

• Lift each blade and check the rubber for splits, hardening or a ragged edge. Smearing, juddering or missed patches mean it is time for new blades.
• Check the windscreen for chips and cracks, which can spread with cold snaps.
• Top up the screenwash with a product that is rated for low temperatures. Plain water can freeze in the bottle and pipes.
• Clear the washer jets if the spray is weak or off target.

Lights

Short days make lights more important. Check every exterior light: dipped and main beam, side lights, fog lights, indicators, brake lights, reversing lights and number plate lights. A helper or a reflection in a shop window or garage door makes this easy. Replace failed bulbs promptly, because a blown bulb can be an MOT failure and, more importantly, makes you harder to see. Cloudy or yellowed headlight lenses can cut the light output noticeably.

Brakes

Wet, salted or icy roads leave little margin. If the pedal feels soft, the car pulls to one side, there is a squeal, grinding or judder, get it checked before winter. Our guide to brake warning signs covers what each one usually means. Brake fluid ages with time too, and we explain why in our guide to brake fluid.

De-icing and visibility

• Keep a proper ice scraper and de-icer in the house or the car, not locked in the boot.
• Clear all the glass and mirrors before driving, not a small peephole.
• Do not pour boiling water on a frozen windscreen; the glass can crack.
• Make sure the heater, demister and rear screen heater all work.

A sensible emergency kit

For a longer journey in winter, it is worth keeping in the car:

• A warm coat, gloves and a blanket
• A torch and a fully charged phone with a charger
• A high-visibility vest and a warning triangle
• Water and a snack
• A small shovel and some grit or an old mat for grip if you are stuck
• Jump leads, or better, a jump starter pack

Breakdown cover details are worth keeping in your phone, too.

Do not forget the basics

Fuel: keep the tank at least a quarter full in winter. A fuller tank means less condensation in the tank and a margin if you are stuck in traffic. Leave plenty of room to stop, and drive smoothly in poor conditions.

Getting it checked

If you would rather not go round the car yourself, our Winter Ready Check covers the battery, tyres, brakes, coolant, wipers and lights. It is £29, and if you book any work with us as a result, the £29 is deducted from that invoice. It is simply a way to find the small things before they leave you stranded.

Talk to us

Prefer someone else to do it? Our Winter Ready Check is £29, deducted from any work you book. Call us on 07746 922 273.