What would cause a Chevy Cobalt to get bad gas mileage?

Poor gas mileage in a Chevy Cobalt can be caused by several factors, including a clogged air filter, which restricts airflow to the engine, or a malfunctioning fuel injector that disrupts the fuel-air mixture. Additionally, issues such as worn spark plugs, low tire pressure, or a failing oxygen sensor can negatively impact fuel efficiency. Regular maintenance, including oil changes and tune-ups, is crucial to ensuring optimal performance and mileage.