1993 Honda Civic Owner's Manual - Page 112

Engine Oil 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. It should look like this: The numbers in the middle tell you the oil's SAE viscosity or weight. Select the oil for your car according to this chart: A fuel-efficient oil is recommended for your Honda. This is shown on the API Service label by the words "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 says "API Service SG." This service rating may also include other designations, such as CD. These additional classifications are not a problem, as long as the label also carries the SG classification. An oil that is only classified SF is not recommended. Ambient temperature An oil with a viscosity of 5W-30 is preferred for improved fuel economy and year-round protection in your Honda. You may use a 10W-30 oil if the temperature in your area never goes below 20°F (-7°C). Additives Your Honda does not need any oil additives. Purchasing additives for the engine or transmission will not increase your car's performance or longevity. It only increases the cost of operating your car. Maintenance