Subaru WRX & WRX STI Manuals 2015 WRX & WRX STI Owner's Manual | Page 513

& Fuel: GAS STATION REFERENCE & Fuel capacity: ! STI The engine is designed to operate at maximum performance using unleaded gasoline with an octane rating of 93 AKI (98 RON) or higher. If 93 AKI (98 RON) fuel is not readily available in your area, unleaded gasoline with an octane rating of 91 AKI (95 RON) may be used with no detriment to engine durability or driveability. However, you may notice a slight decrease in maximum engine performance while using 91 AKI (95 RON) fuel. Use of 91 AKI (95 RON) fuel will not affect your warranty coverage. ! Except STI Use unleaded gasoline with an octane rating of 91 AKI (95 RON) or higher. If 91 AKI (95 RON) fuel is not readily available, unleaded gasoline with an octane rating of 87 AKI (90 RON) may be temporarily used. For optimum engine performance and driveability, it is recommended that you use premium grade unleaded gasoline. 15.9 US gal (60 liters, 13.2 Imp gal) & Fuel octane rating: The indicated oil quantity is only a guideline and is estimated based on a case when the engine oil is changed with an oil filter. After refilling the engine with oil, the oil level should be checked using an oil level gauge. For more details about maintenance and service, refer to “Engine oil” F11-12. This octane rating is the average of the Research Octane and Motor Octane numbers and is commonly referred to as the Anti Knock Index (AKI). Refer to “Fuel octane rating” F7-3. & Engine oil: Use only the following oils. . ILSAC GF-4 or GF-5, which can be identified with the ILSAC certification mark (Starburst mark) . or API classification SN or SM with the words “ENERGY CONSERVING” or “RESOURCE CONSERVING” For the complete viscosity requirements, refer to “Engine oil” F12-4. & Engine oil capacity: ! STI 4.5 US qt (4.3 liters, 3.8 Imp qt) ! Except STI 5.4 US qt (5.1 liters, 4.5 Imp qt) & Cold tire pressure: Refer to “Tires” F12-8.