1997 Nissan Pathfinder Owner's Manual - Page 211

however, meet the API quality and SAE viscosity ratings specified for your vehicle. Do not mix mineral based and synthetic type oils in the engine at the same time. Oil additives NISSAN does not recommend the use of oil additives. The use of an oil additive is not necessary when the proper oil type is used and maintenance intervals are followed. Oil which may contain foreign matter or has been previously used should not be used. STI0077 Oil viscosity The engine oil viscosity or thickness changes with temperature. Because of this, it is important that the engine oil viscosity be selected based on the temperatures at which the vehicle will be operated before the next oil change. The chart "Recommended SAE viscosity number" shows the recommended oil viscosities for the expected ambient temperatures. Choosing an oil viscosity other than that recommended could cause serious engine damage. ENGINE OIL AND OIL FILTER RECOMMENDATION Selecting the correct oil It is essential to choose the correct quality, and viscosity oil to ensure satisfactory engine life and performance. Nissan recommends the use of a low friction oil (energy conserving oil) in order to improve fuel economy and conserve energy. Oils which do not have the specified quality label should not be used as they could cause engine damage. Only those engine oils with the American Petroleum Institute (API) CERTIFICATION MARK on the front of the container should be used. This type of oil supersedes the existing API SG or SH and Energy Conserving II categories. If you cannot find engine oil with the CERTIFICATION MARK, an API SG or SH and Energy Conserving II oil with API Service Symbol may be used. An oil with a single designation "SG" or "SH", or in combination with other categories (for example, "SG/CC" or "SG/CD") may also be used if one with the API CERTIFICATION MARK cannot be found. Mineral based or synthetic type oils may be used in your NISSAN vehicle. These oils must 9-6