Poor Fuel Economy
If fuel economy is lower than expected during a road test, or has decreased since previous road tests, check the following items:
- Ensure air intake system is not restricted or leaking.
- Ensure ignition timing and controls are working properly.
- Check for faulty spark plugs or spark plug wires.
- Ensure engine warms to normal operating temperature.
- Check for low compression.
- Check for restricted exhaust system.
- Check Torque Converter Clutch (TCC) operation.
- Check fuel pressure.
- Check for proper speedometer calibration.
- Verify brakes are not dragging.
- Check for faulty ECM.