Complete Car Maintenance Schedule for Maximum Fuel Economy

Every Month (or 1,000 Miles)

• Check tire pressure — adjust to door jamb specification
• Check engine oil level and color
• Top off HHO reservoir with distilled water (if equipped)
• Visual inspection of belts and hoses

Every 5,000–7,500 Miles

• Engine oil and filter change (synthetic oil)
• Tire rotation
• Air pressure check and adjustment
• Clean MAF sensor if idle quality has changed
• Inspect HHO cell for electrolyte level and current draw

Every 15,000–30,000 Miles

• Air filter inspection and replacement if dirty
• Cabin air filter replacement
• Fuel filter replacement (if external/serviceable)
• PCV valve inspection and replacement
• Throttle body cleaning
• Check valve adjustment (if applicable)
• HHO plate cleaning (vinegar method)

Every 30,000–60,000 Miles

• Spark plug replacement (iridium for longevity)
• Transmission fluid drain and fill
• Coolant system flush and refill
• Fuel injector service (additive or professional)
• Oxygen sensor inspection/replacement on high-mileage sensors
• HHO gasket inspection and replacement if needed

Every 60,000–100,000 Miles

• Timing belt replacement (if applicable)
• Serpentine belt replacement
• Coolant flush
• Complete brake system inspection
• Wheel alignment check
• O2 sensor replacement as preventive maintenance