9 Things You Should Never Do To Your Classic Car In Storage

A classic car that sits all winter faces a long, quiet fight. Damp air, cold nights, old fuel and hungry mice are all waiting for a chance to ruin a good machine.

A vintage car parked inside a warehouse beside shelves of boxes.

Hagerty UK’s article “Sleeping beauty: Follow these experts’ tips for storing your car over winter,” published in November 2021 and written by James Mills, gathers advice from classic car specialists. Many of the lessons turn into plain warnings about what not to do.

Here are nine things you should never do to your classic car in storage, with measurements converted to U.S. terms.

Never Ignore The Moisture In The Garage

Tim Earnshaw of Windrush says moisture is “arguably the biggest killer of most classic cars.” He advises insulating the garage, stopping draughts and fitting a dehumidifier.

Hagerty’s James Mills suggests aiming for about 55% relative humidity. Condensation forms as night temperatures drop, especially in fall and spring.

Never Skip The Fire Protection

Hagerty’s Tim Sawyer recommends a heat-detecting alarm, which will not trigger on exhaust fumes, linked to home alarms if possible. He also advises keeping an extinguisher in the garage.

The article notes this matters most when fuel is stored indoors with a battery charger running.

Never Store The Car Wet

Barney Halse of Classic Heroes says not to put away a wet car, since moisture stays underneath for a long time. He advises driving it or letting the wind dry it before storage.

The article warns that storing a car with wet brakes and the handbrake applied can cause corrosion and “brake pad shadow,” which may require replacing discs and pads.

Never Forget The Tires Can Develop Flat Spots

Ben Field of Vintage Tyres says tires, especially crossplies, can develop flat spots. He suggests inflating them to the highest recommended pressure before storage and checking regularly.

He also recommends rolling the car or rotating the wheels, and restoring the correct pressure before driving. Heavy cars especially need this treatment during a long sit.

Never Trust Old Tires Just Because They Look Fine

The same expert advises inspecting tires for cracking and replacing them at ten years. He points to the four-digit date code on the sidewall as the way to check their age.

A tire can have plenty of tread and still be too old to trust. Read that code before spring.

Never Rely On Disconnecting The Battery Alone

Hagerty’s John Mayhead says that disconnecting the battery alone is not enough, because it still runs down and can develop damaging internal deposits. He recommends a self-monitoring charger suited to your battery type, lead-acid or lithium.

The article cites CTEK, Sealey, Maypole and Clarke as well-rated brands.

Never Store It With A Full Tank Of Treated Fuel Without Thinking

Bill Nathan of Hexagon Classics says he has not found a fuel stabilizer that works, and that fuel degrades. His approach is to store the car with very little fuel, then add about 20 litres, roughly 5 gallons, of fresh premium fuel before restarting.

He also advises checking oil, coolant and brake fluid first. This is one expert’s approach, so ask your own mechanic what suits your car.

Never Start The Engine Just To Hear It Run

Guy Lachlan of Classic Oils says to start the engine occasionally and warm it thoroughly, since most wear happens at start-up and warming drives off water vapor. He stresses ensuring ventilation and avoiding overheating, especially without a radiator fan.

A brief start that never gets the engine warm does little good. Do it properly or leave it alone.

Never Let The Rubber Seals Dry Out

Barney Halse recommends applying silicone grease or spray to door, window, trunk, hood and convertible seals after washing and drying. This prevents them from hardening and perishing.

Hard seals let in water, and replacing them on an old car can be a chore. A can of spray is far cheaper.

None of this is difficult, but all of it needs doing before the first cold snap. Write the list on a card and hang it in the garage.

When the weather warms, your classic will be waiting in good shape, and the first drive of the year will feel like a reward.

Take pictures of the car before it goes into storage, and jot down the mileage, tire pressures and anything you did to prepare it. Those notes make spring waking-up much easier.

Hagerty’s article also includes a tip from a reader comment about mice, which can chew through wiring looms and cause costly repairs. Setting traps in the garage and checking them regularly is a cheap precaution.

Pick a few of these steps and do them well rather than rushing through all nine on the last warm weekend. A classic car is worth the care.

If your classic is a rare one, tell your insurer where it is stored and for how long. A short phone call can clear up questions long before a claim.

Finally, give the car one last wipe-down and a thorough once-over before it goes under its cover. A clean, dry car is a happy car in the cold months.

Plan a spring checklist too: pressures, fluids, brakes and a slow first drive around the block. Easing a car back into service is as important as putting it away.

Steel Horse Rides