How to Store Your Car

You pull into your driveway, take a loving look at the new convertible and realize: Buying it was the fulfillment of a dream. It’s been great fun driving it this summer and fall, but winter is approaching and there’s no way you’re going to drive it on snow and subject it to corrosive road salt—so you face the problem of storing it until late next spring.

A 2- to 4-month driving season followed by eight to 10 months of storage is something many car enthusiasts go through every year. Maybe you’re a snowbird with a pair of vehicles that go into 6-month storage at both your warm- and cold-weather locations during the away season. Even more traumatic: You’ve got a work assignment or a military posting far from home and can’t bring the car. Whatever the vehicle, the reason and the season, you want to be able to store the vehicle without big expense, yet with minimum deterioration and an easy return to operation.

This project was originally published in the October 2002 issue of Popular Mechanics. You can find more great projects at Popular Mechanics DIY Central.

Indoors is always better, particularly for an older vehicle, even if the storage period is summer in the South. If you’re going to be away for up to a couple of years, it definitely has to be kept inside. If you don’t have the place, find an indoor storage facility—it will be money well spent.

In fact, you also should get someone to take out the car periodically for an “exercising” drive. If you can’t afford to do long-term storage right, you might have to pay a lot for restoration when you return.If outdoor “storage” is your only choice, don’t give up. There’s still a lot you can do to minimize the damage, particularly for seasonal storage.

The cleaner the vehicle the better, and that goes beyond wash, wax and shine. Pick a warm, dry day to
do the cleaning. Fill the gas tank, then add an adequate amount of gasoline stabilizer (also made for lawnmowers, snowblowers, etc.) to prevent gum and varnish formation. Drive the car long enough to really warm up the engine and mix the stabilizer with the fuel—at least 30 to 40 miles.

Remove dirt from the underbody, particularly from the wheel wells. Dirt holds moisture, and the combination of moisture and air causes iron and steel to rust. Really, really clean the interior and trunk of the vehicle with a household vacuum cleaner, using those little attachments that reach into nooks and crannies. The battery-powered car vacuum just doesn’t have the suction. The object is to remove all pizza crusts, jellybeans, dog biscuits—anything that could nourish a critter.

Allow the car to air-dry. If the garage or shed has a concrete or earth floor, create a floor vapor barrier with plastic sheeting or tarps. With an earth floor, make a drive-along “path” from strips cut from a sheet of plywood and place them over the vapor barrier. Remove the spark plugs and spray some oil into the cylinders to prevent rust and corrosion. You can use conventional engine oil with a spray-type squirt can or aerosol fogging oil designed for boat storage. Turn the crankshaft (with a socket and ratchet wrench on the crank pulley bolt) about four to six times to circulate the oil.

Reinstall the spark plugs and reconnect the plug wires. Disconnect the battery cables (ground cable first) and remove the battery. Clean the top and sides of the battery to remove any moisture-retaining, conductive film. Place it on a clean, dry surface such as blocks of wood or a polystyrene spacer. Connect a float charger, one designed to maintain a battery charge for long periods. Removing the battery also gives you the chance to inspect the battery box for any corrosion, and to clean it out. Lubricate the hood release latch, hood and door hinges to protect them from moisture. Brake fluid absorbs moisture, which can cause rust and corrosion in the brake system. Flush the old fluid with new.

Long-term storage may call for nonhygroscopic (not moisture-absorbing) silicone fluid. Check the freeze point of the engine coolant with a hydrometer to make sure it’s low enough for the ambient temperatures. Protection from rodents and other critters is important. They not only chew on spark plug wires and other wires, but they can crawl into openings and set up residence. Stuff thick, clean rags into the tailpipe, engine air intake and the fresh air intake in front of the windshield, unless it’s covered by mesh (or a cabin air filter).

If you know you have mice in the area that may enjoy making nesting material out of your cloth rags, use aluminum foil instead. If the vehicle is to be left for six months or longer, the issue of flat-spotting the tires is worth considering. Prevention is straightforward if you have a set of four jackstands. Jack up each end of the vehicle so that it’s high enough to slip a jackstand, in the lowest position, under each lower arm. Jackstands will eventually sink into dirt floors—use plywood squares under them. Stuff clean rags between the wiper arms and windshield to hold the blades off the glass (or remove the blades). This will keep them from sticking to the glass, which could both leave marks and ruin the rubber. Apply a film of rubber lubricant to the squeegees. Empty a large container of mothballs on the floor all around and under the vehicle to discourage critters.

If you must store outside on an earth surface, the best you can do is park the car on a layer of plywood over a continuous layer of heavy-duty plastic. The combination won’t keep all windblown moisture from snow and rain off the underbody. However, to do any better in a windy area you’d have to make the plastic layer oversize. As a final step before placing any cover, lift the ends up and tuck them into the body (trap them in bottom door openings, tape and tie to unpainted trim, etc.) to create a sort of underbody diaper.

This is not easy because you don’t want plastic sheeting against painted metal body parts, where it could trap moisture and cause rust and paint damage. Outdoor storage prep, like indoor, starts with a clean, dry vehicle. Put mothballs in the passenger cabin, laying them on sheets of aluminum foil. Leave each window open a half-inch, so the interior can breathe, but cut some strips of fine screening to cover the openings and tape the strips to glass and molding with masking tape. Be careful not to tape to the car body paint surfaces. Perform all the other indoor prep, including insect-and rodent-proofing and rust and corrosion prevention. Also remove the battery and store it indoors on a float charger.

We’ve saved the toughest topic for last: body covering. The plain fact is that you have to cover the body, and there’s no perfect way to do so. That’s why we say that indoors is No. 1, and outdoors is No. 2— because it’s all that’s left. There are more choices in body covers than we can count, ranging from $20 to over $300. At the lowest price, you’re likely to get just a plastic cover that’s made in a few sizes to fit all vehicles in a specific category (car, SUV, truck). It may not fit well and it can trap moisture underneath, damaging the vehicle finish. It’s intended as a dust and rain cover for a day or two—at best.

Fit is very important, even if the cover is a “breather” (just porous enough to allow air to pass through, but able to restrict moisture). Wind can whip the inner surface of a loose-fitting cover against the paint and when you peel off the cover, the body may look as if the paint had been sanded. As the prices go up, so does the quality of the fit of the covers—and the materials will be more body-friendly. For sunny areas, pick a cover material that keeps out ultraviolet rays to protect the car’s finish.

But also prep the interior surfaces with suitable protectants such as leather conditioner and plastic treatment. If you’re in a wet ’n’ windy area, you can get extra protection by first covering the body paint with soft blankets, tied down with bungee cords. The blankets not only will wick up moisture that gets through, but provide a protective layer under the vehicle cover. A premium breathable custom-fit cover that extends down to cover the wheel wells, and is secured with straps, is your best bet for outside.

It’s driving season, you’ve opened the garage door and you’re eyeing the car. In addition to unpacking, refitting the battery and so forth, sand most of the rust off the brake rotors with some 100-grit sandpaper on a rubber block, and change the engine oil and filter. You should be ready to roll.

Back after the away-from-home work assignment? If you did not opt for the “exercise program,” you’ll need to take your beloved for a serious drive. Just starting the engine and letting it reach operating speed.