Mechanical Failure: An inconvenience anytime it occurs and can be deadly in the winter. Preventative Maintenance (P.M.) is a must. A well maintained vehicle is enjoyable to drive, it lasts longer and it could command a higher resale price.
Some of the following tips can be performed by any do-it-yourselfer. (Others require a professional auto technician.)
Engine Performance: Get engine drivability problems (hard starting, rough idle, stalling diminished power, etc.) corrected at a good repair shop. Cold weather makes problems worse. Replace dirty filters...air, fuel, pvc, tune-up, etc.
Fuel: Put a bottle of a good fuel deicer into your tank once a month to help keep moisture from freezing in the fuel line. Note that a gas tank which is kept filled helps keep moisture from forming.
Oil: Change your oil and oil filter as specified in your manual or more often (every 3,000 miles) if your driving is mostly stop and go or consists of frequent short trips.
Cooling Systems: The cooling system should be completely flushed and refilled about once every 24 months. The level, condition and concentration of the coolant should be checked periodically. (A 50/50 mix of antifreeze and water is usually recommended.) Do-it-yourselfers, never open the radiator cap until the engine has thoroughly cooled! You should check the condition of the drive belts and water pump. The tightness of drive belts, clamps and hoses should be checked by a pro.
Heater/Defroster: The heater and defroster should be in good working condition for passenger comfort and driver visibility.
Windshield Wipers: Replace old blades. If our climate is harsh, purchase rubber clad (winter) blades to fight ice buildup. Stock up on windshield solvent or deicer. You'll be surprised to see how much you will use. Carry an ice-scraper and/or brush.
Battery: The only accurate way to detect a weak battery is with professional equipment; some type of carbon-pile load tester or equal. Routine care: scrape away corrosion from posts and cable connection; clean all surfaces; retighten all connections. If battery caps are removable, check filled level.
Avoid all contact with corrosive deposits and battery acid. Do not smoke at any time around a battery. Wear eye protection and rubber gloves.
Lights: Inspect all lights, replace burned out bulbs; periodically clean all road grime from lenses. To prevent scratches never use a dry rag.
Exhaust System: Your vehicle should be placed on a lift and the exhaust system examined for leaks and corrosion. Your trunk and floor boards should be inspected for small holes. Exhaust fumes can be deadly.
Tires: Worn tires will be of little use in winter weather. Examine tires for thread depth, uneven wear and cupping. Check sidewalls for cuts and nicks. Check tire pressure once a month. Cold weather makes tire pressure lower. Let the tires "cool down" before checking the pressure. Rotate tires, as recommended. Correct tire pressure can be found on your vehicle door jam. Don't forget your most important tire...the spare tire...and make sure that your jack is in good operating condition.
Carry emergency gear: gloves, boots, blankets, flares, a small shovel, sand or kitty litter, tire chains, matches, battery jumper cables and a flashlight. Put a few high energy bars in your glove box. Make sure that your cell phone is charged.