2004 Honda Civic Owner's Manual - Page 155

Adding Engine Oil ENGINE OIL FILL CAP Recommended Engine Oil Oil is a major contributor to your engine's performance and longevity. Always use a premium-grade 5W-20 detergent oil displaying the API Certification Seal. This seal indicates the oil is energy conserving, and that it meets the American Petroleum Institute's latest requirements. Honda Motor Oil is the preferred 5W-20 lubricant for your vehicle. It is highly recommended that you use Honda Motor Oil in your vehicle for optimum engine protection. Make sure the API Certification Seal says ''For Gasoline Engines''. Unscrew and remove the engine oil fill cap on top of the valve cover. Pour in the oil slowly and carefully so you do not spill any. Clean up any spills immediately. Spilled oil could damage components in the engine compartment. Install the engine oil fill cap and tighten it securely. Wait a few minutes and recheck the oil level. Do not fill above the upper mark; you could damage the engine. API CERTIFICATION SEAL 152 Maintenance