Modern cars no longer need tuneups, but that doesn't mean they are maintenance-free. Check your owner's manual for specific maintenance instructions, and keep the following points in mind:

• Spark plugs must be in good condition. Some will last for 100,000 miles, but many need to be replaced more often.
• Check the air filter twice a year, or more often in dusty conditions. A dirty air filter increases fuel consumption and can cause poor performance.
• Inflate tires according to the recommendation in the owner's manual or as shown on a label attached to the driver's door pillar. Underinflated tires are a safety hazard and can cut fuel economy by as much as 2 percent per pound of pressure below the recommended level.
• Take care of car-care "incidentals" that can affect fuel use. For example, a defective radiator thermostat can waste gas by extending the engine's warm-up time or decreasing the engine's operating temperature. A stuck brake caliper can create drag, which also wastes fuel.