General Importance of Vehicle Maintenance

No matter how much safety equipment you have or how well you drive, you are not safe if your vehicle is not in good condition.

If you are forced to use defensive driving emergency avoidance techniques, a properly responsive vehicle substantially increases your chances of pulling off a successful maneuver. Keep your vehicle in good working condition by having the vehicle properly and regularly maintained. If you do not, your car could fail you at a critical moment, and you could find yourself in a serious situation.

Maintenance regimes vary widely from one vehicle to another. Read your automobile owner’s manual carefully to become familiar with your vehicle’s maintenance schedule and requirements.

What Parts of the Vehicle Should I Properly Maintain?


Make sure all lights work and that your light lenses are clean. Check headlights, taillights, directional signals, and interior lights. If your headlights are not working properly, you won’t be able to see potential hazards in your driving path, and others may not be able to see you properly.


Make sure that you regularly clean your windshield inside and out. In addition, regularly change your windshield wipers. The windows are easier to see out of when they are clean.


Make sure that your mirrors are clean and pointed in the correct direction. The mirrors are designed to assist you in keeping track of traffic around your vehicle. Defensive driving skills include using your peripheral vision. You must know what is around your vehicle at all times while you are driving.


Make sure that your tires are properly inflated and not excessively worn. Tires are designed to grip the road and provide directional control. Bald, worn, or improperly inflated tires decrease your ability to control the vehicle. Rotating your tires helps prolong tire life and improves fuel economy. On most vehicles, tires should be rotated about twice a year; however, you should consult your owner’s manual for the recommended rotation pattern and frequency that suits your own vehicle.Rolling resistance is a key factor that affects a vehicle’s fuel efficiency. Rolling resistance results in premature tread wear when your tires are under-inflated, which also increases fuel consumption. The best way to reduce rolling resistance is to maintain correct tire pressure. Operating a vehicle with just one tire under-inflated by six pounds per square inch (PSI) can substantially reduce the life of the tire and increase the vehicle’s fuel consumption by three percent.Tire pressure needs special attention in cold weather. Tire pressure can be expected to drop by about one PSI for every 10 degree drop in temperature. Tires also lose a certain amount of pressure due to their permeability (by some estimates, as much as two PSI per month). Tire pressure should be checked when the tires are cold (for instance, when the vehicle has been stationary for at least three hours).Wheel alignment should be checked once a year. Misaligned tires drag and do not roll freely as they should. Again, this increases fuel consumption and reduces tire life. Most importantly, improper wheel alignment can cause problems with the vehicle’s handling and ride. While driving, you can perform a self-check on your wheel alignment. On a straight, flat, and traffic-free stretch of road, rest your hands lightly on the steering wheel and drive at an even speed. If the vehicle pulls to one side, the wheels may be misaligned.If you must perform an aggressive avoidance maneuver, you may over- or under-estimate your reaction. If your tires are worn, under inflated, or misaligned, your anticipatory judgment will be off.Wheels should also be balanced. If the vehicle’s tires are out of balance, the driver will feel a pounding or shaking through the steering wheel. This pounding shortens the life of other suspension components and produces uneven tire wear, which increases fuel consumption and decreases predictability of maneuvers. Tires that are not balanced exhibit a wear pattern that looks like a series of bald spots.Remember, don’t neglect the spare tire. Make sure the necessary tools for replacing a tire are appropriately accessible.You should check tire pressure and look for signs of uneven wear or embedded objects that can cause air leaks. In winter, check tire pressure whenever there is a sharp change in temperature.


Cars must be properly lubricated in order to run well. Oil lubricates the moving parts of the engine, minimizing metal-to-metal contact, thereby reducing friction and carrying away excess heat. Oil also captures dirt, metal shavings, and other impurities from the engine and transfers these injurious substances into the vehicle’s oil filter. For best engine performance, fuel efficiency, and reduced emissions, use only the oil recommended in your vehicle owner’s manual. Regular engine oil changes typically cost between $40 and $70 – a far cry from the expense of replacing or rebuilding an engine!Check around the car and under the engine for fluid leaks. Generally, you can often identify the type of fluid that is leaking by its color. Oil is black, coolant is a bright greenish yellow, automatic transmission fluid is pink, and power steering and brake fluids are clear, with a slight brown tinge. All of these fluids are oily to the touch.

Belts, Hoses, Regular Tune-Ups

Have your belts and hoses checked at the regularly scheduled time periods mentioned in your vehicle owner’s manual. Also, get a tune-up at the scheduled maintenance time. Check under the hood for cracked or split spark plug wires, cracked radiator hoses, or loose clamps and corrosion around the battery terminals.

Emission Control Systems

Modern vehicles are equipped to treat exhaust emissions before they are released into the atmosphere. The emission control system must be inspected and maintained according to the manufacturer’s recommendations. If you experience problems such as stalling or poor acceleration, or if your exhaust produces black or blue smoke, your vehicle is probably polluting the air and needs servicing.

Ignition System

Proper maintenance of your vehicle’s ignition system is critical. Spark plugs ignite the air-fuel mixture. If one or more of the plugs is worn or malfunctioning, the engine will misfire, and some fuel will remain unburned. Worn or damaged spark plug wires can also cause misfiring. A misfiring engine wastes fuel, produces higher levels of emissions, and generally performs poorly.


Every motor vehicle must have two braking systems ─ a standard hydraulic (service) brake and a parking brake. The standard foot pedal brake on your passenger vehicle should be able to stop the vehicle traveling 20 miles per hour within a distance of 25 feet when on dry asphalt or a concrete pavement surface free from loose material where the grade does not exceed one percent. Large combination trucks typically require at least 50 feet of stopping distance when braked from the same speed! The parking brake should be adequate to stop and hold the vehicle.While driving, you can perform a self-check on your brake system. On a straight, flat, and traffic-free stretch of road, rest your hands lightly on the steering wheel and apply the brakes gradually. If the vehicle swerves to one side, one of the brake linings may be worn more than the other, or the brakes may need adjustment. If this happens, make sure to get the vehicle to a proper mechanic as soon as possible.

Why Should I Bother to Do Vehicle Maintenance?

Simple ─ the vehicle will last longer and work better.

Defensive driving techniques depend on all vehicular systems working together to achieve the proper response while maneuvering.

The time to find out that your car has a problem is in your driveway, not out on the roadway. Additionally, a properly maintained vehicle is a safer vehicle. With proper maintenance, your vehicle will function as advertised, increasing the potential for you to come through an emergency situation in one piece.

Maintenance requirements vary widely from one vehicle to another. In addition to being able to rely on your vehicle’s performance, especially in times of emergency, and maximizing fuel economy, there is one other extremely important reason to properly maintain your vehicle. Failing to follow your particular vehicle owner manual’s maintenance regime could void your vehicle’s warranty. To keep the manufacturer’s warranty valid, your vehicle must be maintained to the standards recommended in the owner’s manual.