Winter is coming, and without an El Niño or La Niña, we could face large swings in temperature and precipitation. In fact, many parts of the country have already seen hefty snowfall. With our unpredictable weather, odds are that people who live in snow zones are going to have to deal with ice, sleet, snow or a perfect wintry trifecta. Unless you live in sunny climes or are car-free, it’s a good idea to prepare your vehicle now.

I speak from experience — four decades and tens of thousands of miles navigating both Colorado’s high country passes and the streets of Denver in pelting sleet and our infamous “bomb cyclone” this past March. In fact, I just switched to snow tires in anticipation of a pending storm.

Granted, it might not seem so urgent elsewhere. Bruce Jenkins is AAA Mid-Atlantic’s manager of fleet club operations, overseeing service trucks and tow vehicles. He says D.C.-area car owners tend to procrastinate. “We don’t have much snow, but when we do get a few inches or ice, then everyone panics. It’s so much easier if drivers prepare their car now and do a little preventative maintenance.”

Where you live or travel — I’m looking at you, snow-sport enthusiasts — affects what you may need to do to your vehicle and when. Here’s a general plan for winterizing your car.

During the fall

Ensure your tires are properly inflated. Low tire pressure affects braking distances and makes a car harder to steer, and the wild temperature swings we see in the winter can wreak havoc on our tires. According to Tom Williams, Discount Tire’s senior vice president of customer experience, for every 10 degrees the temperature drops, tires lose one pound of pressure per square inch. During a cold snap, your vehicle’s tire pressure-monitoring system light could start flashing on your dash. Head to your local tire store or, if you are a DIYer, consider buying a portable electric air pump from an auto-supply or home-improvement store. You can find your vehicle’s recommended tire pressure on a placard on the driver-side doorjamb

Perform the penny test. Tire tread depth is critical to stopping ability. The easiest way to check it is using the “penny test,” Williams says. Insert an upside-down penny into several grooves of your tires. If you can see all Lincoln’s head, then your tread depth is less than 2/32 of an inch, and your tires need to be replaced.

Decide if you want winter tires. Unless you live in a region prone to prolonged periods of ice and snow or plan to drive to such areas, all-season tires should suit you fine. For those facing months of temperatures below 45 degrees, a second set of winter tires makes sense. Winter tires contain thousands of edges for a biting grip, and the rubber remains pliable in cold weather to improve stopping distance and traction, Williams says. They run $125 to $150 per tire, but by swapping them for your all-weathers after six months, you extend the life of both sets. Even if you aren’t going to buy snow tires, replace worn-out tires in the fall. Newer tires will have more tread, and more tread equals greater traction. Plus, tire stores typically hold fall sales, so you may save a few bucks.

Go under the hood. When the weather turns cold, oils and other engine fluids thicken. That means the battery needs more oomph to start an engine, so you’ll want to pop the hood and check the charge. At the same time, inspect belts and hoses for any cracks or breaks. (Local car care shops will often do a free winter car check, testing the battery and inspecting your car’s fluids, filters, hoses and wipers.) Check the label on your windshield wiper fluid to ensure it is rated for winter, usually to minus-20 degrees. I accidentally left “summer” wiper fluid in my car once, only to have it freeze solid. Now, I set it for winter year-round.

Pull out the owner’s manual. What’s worse than having to pull off the road during a whiteout because your windshield wipers are covered with snow? Not being able to clean off the wipers. Some higher-end cars “hide” windshield wipers in a well so the car is more aesthetically pleasing. I can tell you from personal experience, though the car may look pretty, it’s awful to have to figure out how to get the wipers up and away from the windshield (into what is called “maintenance mode”) in a snowstorm. It may involve pushing buttons or turning dials in a specific sequence. Grab your owner’s manual in advance and practice how to access your wipers, pop the hood or refill the wiper fluid well.

Mix up your own ice breaker. This winter hack, which really works, comes from Knoxville, Tenn., TV weatherman Ken Weathers (yes, that’s his real name). Fill a spray bottle with one-third part water and two-thirds parts 91 percent isopropyl alcohol to create your own ice-melting solution. Because the freezing point of rubbing alcohol is so low, it breaks up the ice almost instantly, and you can keep this spray bottle in your car to use anytime. The diluted alcohol shouldn’t hurt your wipers, just try to keep it off painted areas.

During the winter

Start your car’s engine regularly. If you aren’t driving your car on a regular basis, start the engine every few days. If it’s really cold — say around or below freezing — start it daily. Today’s vehicles have all sorts of processes running even when the engine is off — a digital clock, security system, Bluetooth. They may not seem like much, but together they present a small, constant drain on your car’s battery. You don’t want to really need your car only to find a dead battery. Prefer to park it and forget it? Consider a drip charger, which plugs into an electrical outlet and is connected to your battery to maintain the charge. They run about $40 to $50 and are easy to use.

De-ice more easily. Should you wake up to your car covered in ice or snow, “Let the car do the work for you,” Jenkins says. “Start your car, turn the defrosters on high, wait several minutes, then start to scrape off any ice.” This is also the perfect time to use your home-brewed ice breaker. Don’t turn on your wipers until the ice is melted. Use a good plastic scraper. Avoid metal ones as they may scratch the windshield and windows.

Remove all snow. Not just from the hood, windows and sides, but the top, too. If you leave inches of snow on top of your car, when you drive off it could break up and blow into the car behind you or slide onto your windshield when you come to a stop. One of the easiest tools for clearing your car is an extension brush (about $15 or less). Some telescope out to four feet and compact down for easy storage. A soft bristle model won’t scratch your paint. Even if you park in a garage, take a moment to spray a bit of window cleaner onto a paper towel and wipe off any dirt or grime from your rear camera so you can see clearly when you put the car in reverse.

Find a good carwash. Those liquid chemicals that crews spray on highways and thoroughfares to reduce ice and melt snow are not your car’s friend once the asphalt is clear. After every storm in which you drive on treated roads, visit a carwash that washes the top and sides and sprays underneath the chassis and into the wheel wells. That should help prevent corrosion.

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