Symptom Definition
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 Pontiac Grand Prix, 2003 Pontiac Bonneville, 2003 Chevrolet Monte Carlo, 2003 Chevrolet Impala, and 2003 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
Fuel economy, as measured by an actual road test is noticeably lower than expected. Also, economy is noticeably lower than the fuel economy was on this vehicle at one time, as previously shown by an actual road test.