How to store your BMW for winter: a complete guide

If you want to store your BMW for winter, a little preparation makes a big difference. Salt, wet roads and cold starts are hard on any car, and especially on a classic or high-performance BMW M car. But a car that simply stands for months without preparation can suffer too.

In this guide we go step by step through everything you need: where to store the car, cleaning, fuel, oil, battery, tyres, protection against rodents and how to bring the car back to life in spring.

Where to store your BMW for winter

The ideal storage place is dry, clean, secure and has a stable temperature. A private garage is perfect if it is not damp. Humidity is the biggest enemy of a stored car, because it causes corrosion, mould in the interior and problems with electrical contacts.

If your garage is damp, consider a dehumidifier or a professional storage facility. Many cities have storage companies for classic and sports cars, often with climate control, battery care and insurance.

Make sure the place is secure and that you can reach a power socket for a battery maintainer. Avoid storing the car next to chemicals, garden fertiliser or anything that produces fumes.

Outdoor storage under a cover is the least good option, but sometimes the only one. In that case use an outdoor cover that is waterproof and breathable, and check the car regularly.

Clean the car inside and out

Never store a dirty car. Road salt, bird droppings, insects and dust can damage the paint and the metal while the car stands.

Wash the car thoroughly, including the underbody and the wheel arches, where salt and mud collect. Let it dry completely, ideally with a short drive so that the brakes and the exhaust system also dry. Then apply a good wax or sealant to protect the paint.

Clean the wheels and the brakes, and treat rubber seals with a suitable care product so they do not stick or crack.

Inside, vacuum the carpets and remove all food, drinks and rubbish: they attract rodents and insects. Clean and condition leather seats. If the interior feels damp, leave a moisture absorber inside during storage.

Fuel and oil

Fill the fuel tank before storage. A full tank leaves less space for air and moisture, which reduces condensation and corrosion inside the tank. If the car will stand for many months, a fuel stabiliser can help keep the fuel fresh. Follow the instructions of the product, and drive a few kilometres afterwards so the treated fuel reaches the whole system.

Change the engine oil and the filter before storage, not after. Used oil contains acids and moisture that can harm the engine during a long rest. Fresh oil protects the internal parts much better.

Check the other fluids too: coolant with the correct antifreeze protection, brake fluid and washer fluid with antifreeze. Brake fluid absorbs water over time, so if it is due for a change, do it before or right after the winter.

Battery care

A modern BMW uses a small amount of electricity even when it is switched off. After a few weeks, the battery can be flat, and a deeply discharged battery may never fully recover.

The best solution is a smart battery maintainer, also called a trickle charger or conditioner. It keeps the battery at the right level without overcharging it. Many BMWs have a jump-start point in the engine compartment that can be used for connecting it; check the owner's handbook for the correct connection points and procedure.

If you cannot use a maintainer, you can disconnect the battery, but this resets some settings and may require the windows and other systems to be re-initialised. On modern BMWs, a maintainer is the better choice.

Do not start the engine every week just to "charge the battery". A short run does not recharge it properly, and the engine never gets warm, which creates moisture in the oil and the exhaust.

Tyres and brakes

When a car stands for months, the tyres can develop flat spots where they touch the ground. This is especially true for high-performance tyres and in cold temperatures.

Increase the tyre pressure moderately above normal for storage, within the maximum shown on the tyre, and write a note on the steering wheel to reduce it again in spring. If possible, move the car a little every few weeks so the tyres rest on a different spot. Some owners use special tyre cradles or put the car on stands for long storage.

Do not leave the handbrake on for months, because the brake pads can stick to the discs. Instead, use wheel chocks and leave the car in gear (manual) or in park (automatic).

Before storage, it is also a good time to check the brake discs, pads and tyres, so that any parts can be ordered and fitted during the winter.

Protect against rodents and moisture

Mice and martens can cause serious damage to a stored car. They chew wiring, hoses and insulation, and they build nests in the air filter box or the interior.

Keep the storage area clean and free of food. Some owners place traps around the car, never inside it. Ultrasonic devices and special sprays are also used, with mixed results. Covering the exhaust tips and the air intake with a breathable cloth or a fine mesh can stop small animals from getting in. Leave a visible reminder to remove these covers before you start the engine.

Use a breathable indoor car cover. It keeps dust off and still lets moisture escape. Never use a plastic sheet indoors: it traps moisture against the paint.

Open the windows a tiny bit if the storage place is secure, or leave a moisture absorber inside, so that the interior does not become musty.

Waking the car up in spring

When the winter is over, bring the car back to life carefully:

• Remove all covers, including the exhaust and air intake covers.
• Check for signs of rodents under the bonnet and in the interior.
• Check the fluid levels and look under the car for leaks.
• Set the tyre pressures back to normal.
• Reconnect or check the battery.
• Start the engine and let it run for a short time while you check for warning lights.
• Drive gently for the first kilometres, and test the brakes carefully: a thin layer of rust on the discs is normal and disappears quickly.

Finally, give the car a fresh wash and enjoy the first drive of the season. A well-stored car feels exactly as good as it did in autumn.

Winter storage checklist

Item Details

Storage place Dry, secure, stable temperature, power socket

Before storage Wash, dry, wax, clean interior

Fuel Full tank, fuel stabiliser for long storage

Oil Fresh oil and filter before storage

Battery Smart battery maintainer

Tyres Slightly higher pressure, move the car or use stands

Brakes Handbrake off, wheel chocks

Cover Breathable indoor cover, never plastic

Frequently asked questions

Should I start my stored car every week?

No. A short run does not charge the battery properly and the engine never gets warm, which creates moisture. It is better to use a battery maintainer and leave the car resting.

Should I store my car with a full tank?

Yes. A full tank reduces condensation inside the tank. For long storage, a fuel stabiliser helps keep the fuel fresh.

Should I leave the handbrake on during storage?

No. The pads can stick to the discs. Use wheel chocks and leave the car in gear or in park instead.

How do I protect my car from mice in winter?

Keep the area clean and free of food, cover the exhaust and air intake with a breathable material, and place traps around the car. Check under the bonnet regularly.

Do I need to change the oil before winter storage?

Yes. Used oil contains acids and moisture. Changing the oil and filter before storage protects the engine during the months it does not run.

Sources

• BMW owner's handbooks – vehicle storage, battery and tyre care
• BMW Group – care and maintenance advice for BMW vehicles