Poor Fuel Economy

Ensure engine operates at normal operating temperature. See appropriate procedures in COOLING SYSTEM CONCERNS - ENGINE OVERHEATING or COOLING SYSTEM CONCERNS - ENGINE RUNS COLD .
Check transaxle fluid level and quality.
Check secondary ignition system. See TEST JB: IGNITION MISFIRE UNDER LOAD under SYSTEM TESTS in SELF-DIAGNOSTICS - VILLAGER article.
Check intake air system. See TEST HU: AIR INTAKE & THROTTLE BODY under SYSTEM TESTS in SELF-DIAGNOSTICS - VILLAGER article.
Check fuel delivery system. See TEST HC: FUEL DELIVERY SYSTEM under SYSTEM TESTS in SELF-DIAGNOSTICS - VILLAGER article.
Check exhaust system. See TEST HF: CATALYST EFFICIENCY MONITOR & EXHAUST SYSTEMS , step 5) under SYSTEM TESTS in SELF-DIAGNOSTICS - VILLAGER article.
Check engine mechanical condition. Check compression, camshaft, valve train components, etc. Repair as necessary. See appropriate article in ENGINES.
Check for proper tire pressure.
Check brake system for malfunction (dragging). See DISC & DRUM - VILLAGER article.
Ensure transaxle is operating properly and not slipping. See AUTOMATIC TRANSAXLE/TRANSMISSION article in AUTOMATIC TRANSMISSIONS.
Check odometer calibration.
Check for correct PCV valve.
Check Mass Air Flow (MAF) sensor for contamination.
Check for intermittent faults. See INTERMITTENT PROBLEM DIAGNOSIS .