1. Change in driving habits: Have you been driving more aggressively, such as accelerating quickly or braking suddenly? This can lead to decreased gas mileage.
2. Tire pressure: Check your tire pressure and make sure it is at the recommended level. Underinflated tires can increase rolling resistance and reduce gas mileage.
3. Air filter: A dirty air filter can restrict airflow to the engine, causing it to work harder and use more gas. Replace your air filter every 12,000 miles or as recommended by your vehicle's manufacturer.
4. Spark plugs: Worn-out spark plugs can cause the engine to misfire, which can lead to decreased gas mileage. Replace your spark plugs every 30,000 miles or as recommended by your vehicle's manufacturer.
5. Oxygen sensor: A faulty oxygen sensor can cause the engine to run rich, which can lead to decreased gas mileage. Replace your oxygen sensor every 90,000 miles or as recommended by your vehicle's manufacturer.
6. Fuel injector: A faulty fuel injector can cause the engine to run rich, which can lead to decreased gas mileage. Replace your fuel injectors every 60,000 miles or as recommended by your vehicle's manufacturer.
7. Catalytic converter: A clogged catalytic converter can restrict exhaust flow, causing the engine to work harder and use more gas. Replace your catalytic converter every 100,000 miles or as recommended by your vehicle's manufacturer.
8. Transmission problems: If your transmission is slipping or shifting erratically, it can cause the engine to work harder and use more gas. Have your transmission checked by a qualified mechanic.
9. Engine problems: If your engine is not running properly, it can lead to decreased gas mileage. Have your engine checked by a qualified mechanic.
10. Bad gas: If you have filled your tank with bad gas, it can cause your engine to run poorly and use more gas. Try draining the bad gas and refilling your tank with good gas.
11. Weight in the trunk: Excess weight in the trunk can reduce gas mileage. Remove any unnecessary items from your trunk.
