How to Protect Your Car When It's Parked Outside

Kathy deWitt / Alamy Stock Photo

 

En español | If you have a garage, use it — and not just for bikes, paint and tools. Keep your car in it.

Your car will look better longer, and that could mean more money for you at sale or trade-in time. And some items may need attention less often if a vehicle is kept indoors, meaning fewer dollars out of your pocket. That's important as we struggle through this twin threat of illness from the coronavirus and uncertain income as jobs are lost and investments shrink.

You could consider a portable, temporary car shelter to protect your vehicle from harsh sun that fades paint and from bird and tree droppings that etch its finish.

After a season when oaks dropped acorns so heavy that the result looked like hail damage, we bought a shelter. Basically tents with no sides, these can be a pain to erect and hard to position so they don't dominate the driveway. And they're ugly. But they work.

An alternative: a fitted car cover. The best are water-resistant and breathable. A waterproof cover can trap moisture and damage a car's paint.

But any car cover needs to be placed on a clean, dry car. Even a water-resistant one can keep enough moisture underneath to mar the paint, and a cover tossed over a dirty car may allow smeared dirt to scratch the finish.

A cover with a cable lock that loops under the car keeps others from taking it off without your knowledge, but it's annoying to use.

If you don't want a cover, you can prolong the life of your car outside in other ways.

The best way to wash

Wash it often. You'll keep paint-damaging debris from accumulating.

"Wash your car weekly if it's parked outside. Acid rain and bird droppings can damage the finish. And an afternoon spent washing, vacuuming and waxing your vehicle will burn about 1,100 calories. It is also a great stress reliever!” advises AAA, the motorists’ organization once known as the American Automobile Association.

If you use a commercial car wash, pick one where humans do the work by hand — no brushes, which can scratch. Find a place where the drying crew uses fresh towels for each car. Commercial washes will scrub underneath a car, especially important after a sloppy winter.

“Have an underbody flush to get that brine and residual stuff out of there. It's very aggressive in how it corrodes,” says Dave Cappert, of the National Institute for Automotive Service Excellence, based in Leesburg, Virginia. The organization certifies technicians in automotive specialties. Cappert focuses on air-conditioning, drivability and electronic repairs.

Try to avoid both the brushless and brush-style drive-through car washes, often found at gas stations. Both can scratch the finish.

If you wash the car yourself, use car-wash soap, not dish soap. Dish soap removes grease, but it strips the chemicals that give the paint on your car its long-lasting shine.

To apply soapy water and for most cleaning on the exterior, microfiber is the key. Use a microfiber cloth or mitt to wash, a microfiber towel to dry and a microfiber cloth to buff car wax. You may use a special sponge applicator to apply wax, which also preserves the paint.

The microfibers can dry as much as a cotton cloth four times their size. They reach where others don't. They also won't hold grime and debris that can scratch the finish and peel the oils from your paint. A cotton towel or a leather chamois can do both.

Keep a spray bottle of what's called “detailer” at the ready. Do you see bird poop or other spots you can't wash until later? To clean it quickly, spray with detailer and wipe with a microfiber cloth.

For glass, use microfiber and automotive glass cleaner, though you can achieve good results with regular window glass cleaner and newspaper. The ink doesn't stain or streak the glass but can leave your hands dirty. The newspaper sheds bits and pieces, but those aren't hard to remove.

Don't forget the sunroof

If your car has a sunroof, Cappert suggests opening the glass or metal panel to make sure drain holes in the corners aren't clogged with debris. Pine needles are a frequent culprit.

Pour water onto the opening's holes while a helper watches for it to drain below the front doors for the front openings or below the back of the car near the rear bumper for the rear openings. If the water is not draining, it will wind up inside the car eventually.

Do not use air pressure or a stiff piece of wire to unclog the holes, Cappert says. The rubber drain tubes can rupture and create a bigger problem. Instead, take your vehicle to a shop for help.

Use the AARP Auto Buying Program for a hassle-free purchase experience

Remove leaves, pine needles and tree pollen from vents at the base of the windshield. If not, the detritus can work into the heating and air-conditioning system and hamper its performance, he says. You'll need the AC for defogging the windshield on damp days, not just for cooling.

"The debris can retain moisture” if the clog gets bad, Cappert says. “And once you get moisture, you get mold.”

Not up to doing it yourself? Hire somebody. It will cost less now than later.

Mind the battery

A car's battery will run down even if the vehicle is off.

"The battery has a parasitic draw at all times — multiple computers on board, comfort and convenience things such as memory seats and stored radio choices. Those take battery power to remember the settings,” Cappert says.

A car battery's life depends on many factors, but figure a new one will last three to four years. Popular Mechanics says six years; you won't find a consensus.

If your battery was new in 2016, this season begins your period of borrowed time. A service shop and some auto parts stores can test your battery's change. To get a hint, look at the battery terminals.

"Terminal cleanliness is a forgotten thing,” Cappert says. If you see green leakage around either electrical contact, the buildup eventually will impair the connection.

You can clean the terminals yourself by unhooking the cables from the terminals and applying baking soda and water with an old toothbrush. But you will have to reset the clock and all those convenience settings that the battery keeps powered.

"A service professional can hook up a temporary battery maintainer and keep the settings from getting lost while the battery's cleaned,” Cappert says.

Drive it at least once a week

This might not be on your to-do list if you work from home or send someone else to get groceries and medicine. But climb in, fire it up, and run it 15 or 20 miles up and down the highway.

That will help keep the battery charged.

And it warms up the oil enough to drive off moisture that can damage the engine. It pumps the oil onto the engine's internal surfaces to keep them properly slick to reduce wear the next time you start the engine — the when an engine experiences the most wear and tear.

Warming the car up will also keep lubrication moving inside the transmission. If it's an old-school four-wheel drive, yank the lever or push the button or turn the knob to engage the 4x4 setting so the gears that drive the two wheels not normally powered get lubed, too.

"Cars don't deal well with being static. Drive once a week for 15 to 30 minutes” and not a stop-and-go dawdle to the corner and back, Cappert says. “Short trips don't do any favors."

You must generate enough heat for long enough to burn off moisture that collects in the fuel and exhaust systems. If you don't, you'll get damaging rust.

Security is part of the equation

• Lock it. Even in an area without much theft, an unlocked car parked outside is an invitation to mischief. Worse: An unsupervised youngster could climb in and get the car rolling or get stuck inside on a hot day.

• Close it. Leaving the windows or sunroof open, even a bit, can let in weather extremes that damage your interior. If it's extraordinarily hot where you are, leave the windows open a bit when parking for a short time to let heated air escape before you climb back in.

• Park it thoughtfully. If your car is parked where you live, try to keep the area lighted to discourage vandalism. To minimize door dings in a parking lot, try to find a well-lit spot that won't invite others to park immediately next to you.

• Hide or remove valuables. Thieves often walk down lines of cars in crowded parking lots in daylight and glance inside for a purse, briefcase or smartphone. Then they smash a window for a quick grab.

Don't skimp on maintenance

Your dashboard's service reminder will alert you to your next recommended service. If it doesn't have that feature, the owner's manual will tell you.

Sometimes the recommendation is every 5,000 miles or six months, whichever comes first. If your car is not used much, schedule service appointments based on time instead of mileage.

Time can degrade gaskets, hoses and lubricants. Tires lose up to two pounds of air pressure a month. That's all accelerated if a car sits outside.

The correct pressure isn't what's printed on the tire sidewall; that's a maximum. The right pressure is listed on a sticker on the driver's doorjamb.

For every 10 degrees of temperature drop, a tire can lose a pound or so of pressure. That's mainly a seasonal danger when days are warm and nights are chilly, leaving you with underinflated tires the next morning. But incorrectly inflated tires are unsafe and wear out faster.

Lack of driving is no reason to skimp on maintenance. Otherwise, your car might leave you stranded when you do need to get somewhere.

More on Cars and Safety

• Avoiding coronavirus risk during car maintenance
• 10 top items for your car-safety checklist
• Don't let pavement markings confuse you