Save money and help the environment by practicing good habits on and off the road. When you drive, follow a few simple rules, improve efficiency, and save money at the same time.
• Keep your car well maintained. A dirty air filter reduces gas mileage by up to 20 percent. Spark plugs that are in poor condition can cut up to 12 percent off your gas mileage.
• Keep tires aligned and properly inflated. Underinflated tires are like driving with the parking brake set, decreasing fuel economy by 25 percent. Overinflated tires also cut into fuel efficiency. Misaligned tires drag down fuel efficiency by nearly 10 percent. Alignment problems cause tires to wear unevenly, further reducing gas mileage. Rotate and balance tires according to the car's owners manual.
• Buy gas during the coolest times of the day, either early morning or in the evening. Gas is denser at these times, so you get more gas for your money.
Do not top off your tank. Stop fueling when the nozzle automatically stops.
• Tighten the gas cap. Damaged, loose or missing gas caps allow gasoline to vaporize from your tank.
• Use the lowest octane level recommended by your owner's manual.
• Use the oil grade recommended by your car's manufacturer. This improves gas mileage up to two percent.
• Drive at a moderate, consistent speed. Accelerate slowly and brake over longer distances. This is the most effective step to reduce fuel costs. Aggressive driving by speeding, rapid acceleration, and frequent braking eat up gas. Drive sensibly and improve gas mileage by five percent in the city and up to 22 percent on the highway.
• Commute and run errands during non-peak traffic times, and reduce idling in traffic. Turn off the engine if you will be idling for more than 30 seconds. Idling uses to to g gallon of gas per hour, much more than restarting a car. Beware of excessive starts and stops of the engine because they increase wear to the starter mechanism.
• Organize your errands and drives. Avoid wasting time and gasoline retracing your route. Complete errands on your way to and from work if possible to reduce fuel use.
• Carry only necessities in your car. Every extra 100 pounds in the trunk reduces gas mileage by up to two percent.
• Improve airflow around your car by removing any add-ons that cause drag, like luggage racks, ski racks, and bike racks.
• Use overdrive gear when possible, and use cruise control on the highway. This helps keep speed consistent and saves gas money. Mileage decreases at speeds over about 60 mph.
• Driving with the air conditioning on is not a factor in gas savings, assuming you do not run your air conditioner with the windows open.