1997 Honda Prelude Owner's Manual - Page 145

Engine Oil Adding Oil ENGINE OIL FILL CAP Recommended Oil Oil is a major contributor to your engine's performance and longevity. Always use a premium-grade detergent oil. You can determine an oil's SAE viscosity and Service Classification from the API Service label on the oil container. A fuel-efficient oil is recommended for your Honda. This is shown on the API Service label by the words "Energy Conserving " or "Energy Conserving II." This oil is formulated to help your engine use less fuel. The API Service label also tells you the service classification of the oil. Always use an oil that is labeled "API Service SJ" or "API Service SH." This service rating may include other classifications, such as CD. These additional classifications are not a problem, as long as the label also carries the SJ or SH classification. An oil that is only classified SG is not recommended. To add oil, unscrew and remove the engine oil fill cap on top of the valve cover. Pour in the oil, and replace the engine oil fill cap. 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 SERVICE LABEL Maintenance