Why is winterizing your car important? Because if your car has any problem, cold weather will make it worse, and you do not want to be stuck on the side of the road in sub-freezing temperature wishing you'd added anti-freeze to your car.
Avoid this situation by winterizing your car each fall before it gets particularly cold (obviously, winterizing is more important in Minnesota than it is in Mississippi). Also, use winterizing as your excuse to give your car an annual check-up and look over all its major components. You can split this work with your mechanic or you can leave it all to the mechanic and simply say, "Winterize my car."
First of all, check the car parts that are particularly key in cold weather. Do your heater and defroster work quickly and effectively? Do all of your lights (both internal and external) have working bulbs? Do your tires have good tread? Do your windshield wipers work well?
Next, you'll want to add some fluids to your car. Anti-freeze, which lubricates the water pump and stops engine corrosion, has a particularly low freezing point; check it every year, and change it every two years. You should also top off your windshield washer solvent (which should be good to ten degrees below zero) and, each month, pour up to one bottle of fuel de-icer into your gas tank to keep moisture from freezing on the fuel line. Finally, replace your traditional motor oil with lighter weight oil, which will help your engine start easily.
In addition to fluids, car owners in some cold-weather climates make additional purchases for their cars. Winter wiper blades have a rubber boot that keeps the pivot points from freezing, and snow tires and tire chains improve your traction on icy roads. A new battery will provide the extra amperage you need to start a cold engine.
Finally, get ready for winter by amending your auto survival kit. Add gloves, a blanket, and an ice scraper to your car at the first hint of cold weather. If you drive anywhere that you might get stranded, it's also a good idea to add food and water, as well as a flare gun, and perhaps sandbags, which you can use for traction on slippery areas.