Most winter car storage advice assumes the car is going into your own garage. Much of it is sound. What almost none of it tells you is which jobs genuinely matter, which are habit passed down, and which you can hand to somebody else entirely.
Here is the full list, in the order we would do it, with a note on what changes if the car goes into secure car storage instead. It applies to a classic, a supercar or an everyday car you simply will not use until spring.
Most owners put a car into winter storage from late October to early April, a period of roughly five to six months. The trigger worth watching is not the calendar but the first application of road salt, which usually follows the first hard frost. Once salt is down, every mile does more harm than the miles before it.
There is an argument for going slightly later than instinct suggests. A dry, bright November day is some of the best driving of the year, and a car that has been run properly before it is put away stores better than one parked in September and forgotten.
Yes, and it is the single most important preparation job. Road grime, salt and bird lime left on paint for five months cause damage that is entirely avoidable. Wash it, dry it completely, and wax the paintwork before it goes away.
Pay particular attention to the underside and the wheel arches, where salt collects and sits unseen. A car that looks clean from three feet away can still be carrying enough salt underneath to start corrosion over winter. Most car storage facilities will wash and dry the car on arrival, but check whether that includes the underside.
Dry it properly rather than leaving it to air dry. Water trapped in shuts, seams and around trim is exactly where rust starts, and it is the part people rush.
Fill the tank to around 95% and add a fuel stabiliser. A full tank leaves less air space for moisture to condense in, which is what causes rust inside the tank and water in the fuel system. Modern petrol containing ethanol degrades faster, which is why stabiliser matters more than it used to.
Run the engine for a few minutes after adding the stabiliser so treated fuel reaches the carburettor or injection system rather than sitting in the tank alone.
If the oil is anywhere near due, change it before storage rather than after. Used engine oil carries acidic combustion by products, and leaving those sitting against bearings and internal surfaces for five months does more harm than the same oil would do in five months of driving.
Fresh oil, a new filter, and a short run to circulate it is a genuinely worthwhile hour. It is also far easier to do in October with the car warm than in April with a car that will not start.
Inflate the tyres above normal running pressure, typically from around 30 PSI up to 35 or 40 PSI, and move the car every few weeks. If the car will be standing for many months without being moved, axle stands take the load off the tyres entirely.
Flat spots form because the same contact patch carries the weight for months. On modern rubber a mild flat spot often works itself out after a few miles. On older crossply or a rare tyre that is expensive or impossible to replace, it may not.
Moving the car a few feet every few weeks is the simplest answer, and it is one of the jobs most likely to be forgotten by an owner and done automatically by a facility.
Connect a smart battery conditioner and leave it connected. A conditioner monitors the battery and charges only when needed, unlike an old trickle charger which can overcharge. If there is no power where the car is stored, disconnect the battery instead, though that means losing radio codes and clock settings.
Batteries left flat over winter sulphate and often will not recover. A healthy 12 volt battery reads about 12.6 volts at rest; below 12.4 volts it is already discharging faster than it should. It is the most common single reason a stored car will not start in spring, and the most easily prevented.
Modern cars with alarms, trackers and permanently live electronics drain far faster than older cars, so a conditioner is close to essential rather than optional.
No. Leave the handbrake off and use chocks instead, or leave the car in gear. Brake pads and shoes left clamped against discs or drums for months can bond to them, particularly in a damp building, and freeing them can mean removing the wheels.
This is one of the small details that separates somebody who has stored a lot of cars from somebody following a checklist. It costs nothing and it prevents a genuinely irritating problem.
Use a soft, breathable indoor cover. Never use a plastic or waterproof outdoor cover on a car stored inside. Non breathable covers trap moisture against the paint and create exactly the damp microclimate you are trying to avoid.
The cover also needs to go on a clean car. Any grit left on the paint will be ground in by the cover moving slightly over five months, which produces fine scratches across the panels.
Damp is the enemy, not cold. Clean the interior thoroughly, remove anything organic, and place moisture absorbers such as silica gel in the footwells. Leaving windows very slightly open helps air circulate, but only in a secure, dry building.
Anything left in the car matters more than owners expect. Crumbs, a forgotten apple core or a damp cloth in the boot will attract mice, and mice in a classic car interior over winter cause the kind of damage nobody budgets for.
Check for gaps where wildlife can get in. Exhaust tailpipes and air intakes are the usual routes, and a piece of steel wool is enough to block them.
A car kept off the road can be declared SORN with the DVLA, which stops the tax and refunds full remaining months. Many owners also move to a laid up or limited mileage policy for the storage period, which is normally cheaper than full cover.
Two things to check before declaring SORN. The car must be kept off the public road entirely, and some insurers require the vehicle to remain insured even while SORN, for fire and theft rather than road risk.
If the MOT expires during storage, arrange it before the car goes away rather than around a car that will not start. Better facilities check that the car is road legal, with valid MOT and tax, before handing it back to you, but that is a check rather than a booking service. Ask which you are getting.
Most of this list stops being your job. A proper car storage facility will inspect and prepare the car, keep the battery conditioned, move it regularly to protect the tyres, run the engine up to operating temperature, and hold the building at a controlled humidity. What you keep is the decision about when it goes in and the drive there.
The distinction worth understanding is between secure car storage that maintains a car and vehicle storage that simply holds it. A lock up garage or a self storage unit does nothing on this list. You will collect a car in April that has been kept, not looked after.
It is worth asking any car storage facility to walk through this list with you and say which items are standard, which are extra, and which they expect you to have done before the car arrives. If you are searching for car storage near you, that single question separates the serious operators from the rest faster than anything on a website.
Not briefly, no. Starting a car and letting it idle for ten minutes is worse than leaving it alone. It introduces moisture into the oil and exhaust without ever getting hot enough to burn it off, so the car ends up damper inside than before it was started.
The advice to start it every couple of weeks is one of the most repeated and least helpful pieces of storage folklore. It comes from an era of different oils and different engines, and it survives because it feels like doing something.
There are two positions that work. Leave the engine alone entirely and address it properly in spring, or run it fully to operating temperature, which in practice means driving it rather than idling it on a forecourt. Anything between the two does harm.
No. It needs a dry one. Good indoor car storage holds relative humidity at roughly 50 to 55%, which is low enough to stop corrosion without drying out leather and rubber. Heat without insulation and humidity control makes things worse, because warm air holds more moisture than cold air and that moisture condenses on cold metal as the building cools overnight.
A cold, dry, well ventilated barn will preserve a car better than a warm, damp garage. This is why serious facilities talk about relative humidity rather than temperature, and why a domestic garage with a heater in it is not the upgrade it appears to be.
If the car is at home, a dehumidifier is a better investment than a heater, and a moisture absorbing product inside the car costs very little.
Check the tyres before moving it, reconnect and test the battery, look underneath for fluid leaks that appeared while it stood, then start it and let it reach full temperature before driving properly. Brakes will often be rusty on the surface and will clean up within a few careful stops.
Give it a slow first few miles. Seals that have not moved for five months, brakes that have surface rust and tyres that have been sitting all behave differently for the first ten minutes than they will for the rest of the year.
It is also the moment to check for anything that got in over winter. Look in the air intake, the exhaust and under the bonnet before the first start rather than after.
Twelve jobs, and who does them. Use this to work out what you are actually taking on, or what you are actually paying for.
Two things. Store the car warm rather than cold, meaning drive it properly before it goes away rather than parking it straight from a cold start. And write down what you did, because in April you will not remember whether you added stabiliser or left the handbrake off.
The rest is unglamorous and it works. Cars that come out in spring exactly as they went in are not lucky. They were prepared properly and then someone paid attention to them while nobody was watching.
Henry’s Car Barn has provided secure car storage since 1984, from sites in Warwickshire, Hampshire, West Sussex, London and Northumberland. The Warwickshire site sits at the end of a mile long drive behind electronic gates with number plate recognition, with convenient access from the M40, M42, M6 and M5.
For anything already with us, the routine is set: a daily inspection of the site, a weekly check of every battery conditioner, and every sixty days each car is uncovered, started, run up to operating temperature and moved to protect the tyres before going back under its cover.
If you would like to talk through what winter car storage would involve for your car, classic or otherwise, get in touch and we will walk you through it honestly, including the parts you could perfectly well do yourself.
