Laying up a classic car for winter, step by step

There is no fixed date. Most owners lay up when the driving season ends and before the roads are salted. Road salt is the main reason. Salt holds water against metal and, according to the Canadian Conservation Institute, salt-contaminated iron can corrode at a relative humidity as low as 20%. A car that has been driven on salted roads and then put away carries that salt into storage.

If you plan to use the car on dry winter days, you need not lay it up fully. Keep the battery charged, wash it after every salty drive and keep the garage dry. Footman James notes that the best way to keep a car from becoming a "barn find" is to use it regularly.

Before the lay-up, check that the place it is going is ready: see damp and condensation for the garage, and mice and rats for proofing.

Change the oil and filter

Used engine oil carries acidic by-products of combustion. Hagerty UK advises changing the oil and filter before the car is put away, because old oil containing acidic material can damage an engine if left for a long time, and many specialists recommend an oil change at least once a year on a lightly used car whatever its mileage. The best time is just before the season's last proper drive, so the fresh oil is circulated and coats the internals before the car stands. Use the grade your handbook or specialist recommends.

Check the coolant

Coolant protects against frost and corrosion. Check its strength with a hydrometer or refractometer; most garages will do it for you. A 50/50 mix of antifreeze and water is the usual strength. Frozen coolant expands and can split radiators, hoses and water pumps, or crack engine castings. The FBHVC advises using the traditional inorganic additive (IAT) type of antifreeze in historic vehicles, using "long life" organic (OAT) types only if the car used them when new, never mixing types without flushing the system, and replacing coolant within the antifreeze maker's recommended interval. If the coolant is old or of unknown type, change it before the lay-up rather than after.

Decide about fuel

This is the step on which the advice differs most. Here is what the main sources say.

The FBHVC position. The Federation of British Historic Vehicle Clubs, which represents historic vehicle clubs in the UK, says:

• long-term storage of petrol containing ethanol, for example over a winter, can lead to corrosion in fuel systems;
• if a vehicle is to be laid up for an extended period, the E10 petrol in it should be replaced with ethanol-free petrol, which some suppliers sell;
• if ethanol-free petrol is not available, carburettor float bowls should be drained, because petrol left in them evaporates and can leave a corrosive water and ethanol residue;
• fuel systems should not be left dry, because rubber seals and gaskets can shrink and crack as they dry out;
• aftermarket corrosion inhibitor additives are recommended for E5 and E10 petrol; the FBHVC no longer endorses particular products.

Full tank. Several sources advise filling the tank before storage, to leave less air space in which moisture can condense and less bare metal exposed inside the tank. Footman James and Hagerty UK both give this advice, usually with a fuel additive. A storage specialist quoted by Footman James says the choice depends on the tank: a steel tank benefits from being full, because less air means less corrosion, while a plastic tank can be left empty.

Nearly empty tank. Others prefer to store with very little fuel and add fresh petrol in spring. A restoration specialist quoted by Hagerty UK in 2021 advised storing a car with very little fuel in the tank and adding around 20 litres of fresh premium petrol on revival. Another Hagerty UK article advised leaving the tank as empty as possible with a stabiliser.

Stabilisers. Fuel stabilisers are additives intended to slow the ageing of petrol. The evidence for them is thin. The RAC says it does not normally recommend their use. The specialist quoted by Hagerty UK said he had yet to find a stabiliser that works. The FBHVC's fuels guidance recommends corrosion inhibitors but does not address stabilisers. If you use one, it is no substitute for fresh fuel in spring.

How long petrol lasts. The RAC puts the shelf life of petrol at about six months in a sealed container at 20°C, and three months at 30°C. A tank in a cool garage is not a sealed container, so fuel left over winter will be past its best by spring whichever approach you take.

What we suggest. For a winter lay-up of a car with a steel tank, fill it with E5 super grade petrol (or ethanol-free petrol if you can get it) on the last drive, with a corrosion inhibitor if you use one, so the tank is full and the fuel has been through the system. That follows the reasoning about air space in a steel tank. E5 still contains some ethanol, though: the FBHVC's preference for an extended lay-up is ethanol-free petrol, and where that is not available it advises draining the carburettor float bowls. If you can only get E10, or the car will stand for many months, draining the float bowls matters all the more. For a lay-up of a year or more, plan to drain and replace the fuel; that is covered in our long-term storage page, in preparation.

Safety. Petrol vapour is highly flammable. Never drain fuel in a closed garage or near a boiler, freezer or any other source of ignition. The HSE says you can store up to 30 litres of petrol at home, away from living accommodation, without having to notify your local petroleum enforcement authority, in suitable containers: plastic ones of up to 10 litres or metal ones of up to 20 litres.

Book any work

If the car needs work over the winter, book it now. A specialist's winter diary fills early, and a car going to a workshop needs different preparation from one standing in your garage.

1. Wash and dry, including underneath

Wash the car thoroughly, paying most attention to the underside, wheel arches, sills and the backs of the wheels where salt and mud collect. Rinse well. Then let it dry completely: drive it gently for a few miles, or leave it with the doors and boot open in a dry garage before covering. Clear drain holes in the doors, sills and floor so water cannot sit inside. Clean and dry the interior, and remove all food, wrappers and rubbish.

2. Park it where it will stay

Put the car where it will spend the winter, with room to walk around it, plug in a charger and run a dehumidifier. Do not park it hard against a wall or under shelves where things can fall on it.

3. Tyres

Tyres resting in one place for months can develop flat spots, a temporary deformation where the tyre has stood. The usual advice is:

• Raise the pressures towards the maximum marked on the sidewall, but never above it. Pirelli advises this to limit deformation, and reminds owners to return to the normal pressure before driving. Hagerty UK gives similar advice.
• Or take the weight off the tyres. Pirelli suggests putting a stored vehicle on blocks so it is not resting on its tyres for a long period. Curved tyre cradles, or squares of foam board under the tyres, spread the load without lifting the car.

Axle stands: pros and cons. Raising the car onto stands removes the risk of flat spots altogether, and some owners prefer it for long lay-ups. Against that, a car on stands cannot be rolled to free its brakes or checked for movement, it has to be raised and lowered safely, and the stands must sit on firm, level ground at the support points given in the workshop manual. For a normal winter, raised pressures and a check every few weeks are usually enough.

Tyres also age. Rubber oxidises and cracks with time, even on a car that hardly moves. Check the date code (see owning a classic), and inspect sidewalls for cracking. A tyre specialist quoted by Hagerty UK recommends changing tyres at ten years. Keep tyres away from electric motors, such as freezer or compressor motors, which produce ozone that attacks rubber.

4. Brakes: handbrake off

Do not leave the handbrake on. Brake shoes and pads left pressed against drums and discs for months can stick, especially in damp air. Chock the wheels front and back, and leave a manual car in gear or an automatic in park. Footman James advises never leaving the handbrake on if the car is parked for more than a few days.

5. Battery

A lead-acid battery slowly discharges while it stands, and deep discharge can damage it beyond recovery. You have two choices.

• Battery conditioner. A battery conditioner or "smart" charger monitors the battery and adjusts its charge, and is designed to be left connected for long periods. Check the instructions confirm it can be left on indefinitely. Place it where it cannot fall, get wet or be knocked, keep the leads tidy, and make sure the battery is ventilated.
• Disconnect. Disconnect the battery, or remove it to somewhere cool, dry and frost-free. Battery maker VARTA advises charging it to around 12.7 to 12.8 volts before storage, checking the voltage every two months, and recharging if it falls to 12.5 volts or less.

Either way, clean the battery top and terminals: VARTA notes that dirt and moisture on a battery allow small leakage currents that drain it faster. A light smear of petroleum jelly on clean terminals helps prevent corrosion. On a car with a battery isolator, turning it off stops any small drains from clocks or radios.

6. Wipers, windows and interior

• Lift the wipers off the screen, or put a soft cloth under the blades, so the rubber does not stick to the glass.
• Windows. Hagerty UK and Footman James suggest leaving a window open slightly to let air circulate and prevent a musty smell. That is sensible in a dry garage with no sign of mice. If there is any chance of rodents, close the windows and rely on moisture absorbers instead; Hagerty UK's own rodent advice is to make sure all windows are closed.
• Moisture absorbers. Tubs of moisture-absorbing crystals or bags of silica gel in the cabin and boot take up damp. Stand tubs in a tray so they cannot spill, and check them on each visit.
• Convertibles. Leave the hood up rather than folded for months, as Hagerty UK advises, so it does not crease, crack or shrink.

7. Block the exhaust and air intake, and tag them

Plug the tailpipe and the air intake or air filter inlet to keep out mice and damp air, using a bung or plug made for the purpose. Avoid plain wire wool for months in a damp garage, because it rusts. Put a bright tag on each plug, and leave a note on the steering wheel listing everything you have fitted or disconnected. Starting the engine with the exhaust or intake blocked can damage it.

8. Rodent proofing

Set your rodent precautions now, while the car is clean: mesh behind the grille and over intakes where practical, traps in tunnels around the garage, and nothing edible anywhere. See mice and rats.

9. Cover

Use a clean, breathable indoor cover in a garage. Make sure the car is dry first. Never use plastic sheeting or a tarpaulin, which trap moisture against the paint. If the car is in an airflow enclosure, zip it up and check the fans run. Do not stack boxes or tools on top of a covered car.

10. Paperwork

Decide now whether the car will stay taxed and insured, or be declared off the road.

• Keep it taxed and insured. If the car is in the historic tax class, tax costs nothing, so many owners keep it taxed and insured, ready for a dry winter day. A taxed car must be insured, even in the garage.
• SORN. A Statutory Off Road Notification means you do not need to tax or insure the car. The car must then not be kept or used on a public road, except when driving to or from a pre-booked MOT or other test. A SORN does not need renewing: it ends when you tax the car again. GOV.UK says you can be fined £80 automatically if a car has neither tax nor a SORN, and driving a car with a SORN can lead to a fine of up to £2,500.
• Laid-up cover. Many classic insurers offer laid-up cover for a car with a SORN, typically covering fire and theft but not driving. Check whether it covers rodent or accidental damage in storage.
• Tell your insurer where the car is kept, especially if it is moving to a different garage or a storage firm.

Before using the car again after a SORN, tax it first, and insure it. See law and security for historic tax and MOT exemption.

Should I start the engine?

Many owners like to start a stored car every few weeks "to keep it healthy". The weight of advice is against this unless you can run it properly.

• An engine that is started and idled for a few minutes does not reach full temperature. Combustion produces water, and in a cold engine and exhaust that water condenses instead of being driven off. Footman James warns that on short runs the oil does not get up to temperature, leaving moisture in the engine that can cause corrosion and wear, and advises not starting the engine every few weeks unless you are going to drive the car. Its later checklist adds that brief idling can cause condensation in the exhaust.
• Hagerty UK says that leaving a car idling in the drive and then switching it off is not good practice.
• A lubricants specialist quoted by Hagerty UK takes a different view, that starting the engine from time to time is a good idea, but only if it is then warmed through thoroughly.

The common ground is clear: either run the car until it is fully warm, ideally by driving it, or leave it alone. A few minutes of idling can do more harm than good. If you do start it, remove every plug and blocker first, open the garage doors fully, and never run an engine in a closed garage: the NHS lists running a vehicle engine in an enclosed space such as a garage as a cause of carbon monoxide poisoning.

A monthly check

Visit the car at least once a month, more often in a thaw or after storms. Take ten minutes to:

1. Read the hygrometer and note the high and low since your last visit.
2. Check the dehumidifier is running, draining and not iced.
3. Check the battery. Look for the conditioner's "charged" or "maintenance" light, or measure the voltage of a disconnected battery (recharge it at 12.5 volts or less).
4. Look for rodents. Droppings, chewed paper, smells; check and reset traps.
5. Look under the car for fresh drips of oil, coolant, fuel or brake fluid.
6. Check the tyres for pressure loss; Footman James suggests checking pressures every few weeks.
7. Check the cover and interior for damp, mould or a musty smell, and empty or replace moisture absorbers.
8. Rock the car gently, if it is safe to roll, so the brakes do not bind. Footman James suggests this; leave the handbrake off and replace the chocks afterwards.
9. Lift the bonnet every month or two and look at belts and hoses for cracking or perishing.
10. Check the garage for leaks after heavy rain, and that doors and locks are secure.

When the days lengthen, resist the urge to start the car and drive off. A detailed page on starting a car after storage is in preparation. In outline:

• Remove every blocker using your list: exhaust plugs, intake plugs, cloths under wipers.
• Check for rodent damage to wiring, pipes, the air filter and the heater (see mice and rats).
• Check the oil and coolant levels, and look for leaks.
• Check the brakes. Release the handbrake fully and check the pedal feels firm. Brake fluid absorbs water from the air over time; if it is due, change it before driving; some specialists advise changing it after every lay-up.
• Reset the tyre pressures to the normal figures, and inspect the tyres.
• Charge or refit the battery.
• Consider the fuel. If the tank was left with old or E10 fuel, add fresh E5 or drain and replace it as planned.
• Tax and insure the car before it goes on the road if it has been declared SORN.
• Start it with the garage doors open, let it warm up, and make the first drive a short, gentle one close to home.

Then wash the car, check underneath for anything that came loose, and enjoy it.