Poor Fuel Economy
- Check tire pressure, dragging brakes, transmission problem, driving habits, etc.
- Check ignition system. See CIRCUIT TEST JA in the TESTS W/CODES article.
- Check fuel delivery system. See CIRCUIT TEST HC in the TESTS W/CODES article.
- Check exhaust system. See CIRCUIT TEST HF in the TESTS W/CODES article.
- Check engine compression and general mechanical condition.
- Check cooling system thermostat (not closing).
- Check for slipping clutch.
- Check odometer calibration.
- Vehicle load or operator driving habits.