2002 Subaru Impreza Owner's Manual - Page 320

Maintenance and service Oil grade: API classification SJ or SH with the words "ENERGY CONSERVING II" (if you cannot obtain the oil with SJ or SH grade, you may use SG grade oil.) or the new API certification mark (Starburst mark) displayed on the container. HGB019AA New API Certification Mark (Starburst Mark) HGB018BB API Service label 1) Indicates the oil quality by API designations 2) Indicates the SAE oil viscosity grade 3) Indicates that the oil has fuel saving capabilities In choosing an oil, you want the proper quality and viscosity, as well as one that will add to fuel economy. The following table lists the recommended viscosities and applicable temperatures. When adding oil, different brands may be used together as long as they are the same API classification and SAE viscosity as those recommended by SUBARU. Engine oil viscosity (thickness) affects fuel economy. Oils of lower viscosity provide better fuel economy. However, in hot weather, oil of higher viscosity is required to properly lubricate the engine. 11-12