It doesn't matter if the car you're driving is new or old, big or small. There are preventive maintenance steps every vehicle owner can take to make sure their car is as "green" or environmentally friendly as possible, according to the Car Care Council.

By following five simple preventive maintenance steps, you can help protect the environment by improving gas mileage, which in turn saves money at the pump.

  1. The first step is to keep your car properly tuned for optimum performance. A well-tuned engine delivers the best balance of power and fuel economy and produces the lowest level of emissions. A 21st Century tune-up for modern vehicles includes the following system checks: battery, charging and starting; engine mechanical; powertrain control (including onboard diagnostic checks); fuel; ignition; and emissions. A 21st Century tune-up can improve gas mileage by an average of four percent. Fixing a serious maintenance problem, such as a faulty oxygen sensor, can improve gas mileage by as much as 40 percent.

  2. The second step is to regularly check and replace dirty air filters. An air filter that is clogged with dirt, dust and bugs chokes off the air and creates a "rich" mixture -- too much gas being burned for the amount of air -- that wastes gas and causes the engine to lose power. Replacing a clogged air filter can improve gas mileage by as much as 10 percent, saving about 15 cents a gallon.

  3. The third step is have the spark plugs checked -- if they haven't already been checked as part of the tune-up -- and replaced if necessary. A vehicle can have four, six or eight spark plugs, which fire as many as 3 million times every 1,000 miles. This results in a lot of heat, electrical, and chemical erosion. A dirty spark plug also causes misfiring, which wastes fuel.

  4. The fourth step is to maintain the cooling system of your vehicle. A cooling system thermostat that causes the engine to run too cold will lower the fuel efficiency of a car by as much as one or two mpg. There also are improved radiator caps on the market today that allow the cooling system to operate at a higher temperature before boiling over, increasing the system's efficiency and reducing emissions.

  5. The last step toward keeping a "green" car is to properly maintain and repair your car as outlined in the council's Car Care Guide. The guide helps drivers understand their car, the care it needs, and when it needs it and why. Single copies of the free guide may be ordered on the Car Care Council Web site, http://www.carcare.org/.

In addition to proper vehicle maintenance, vehicles can be more fuel- efficient if tires are properly inflated and if drivers observe the speed limit, avoid aggressive driving and excessive idling, and adhere to an errand list to eliminate extra trips to the store for forgotten items.