2003 Subaru Outback Owner's Manual - Page 472

GAS STATION REFERENCE Fuel: 2.5 Liter models: Use only unleaded gasoline with an octane rating of 87 AKI or higher. 3.0 Liter models: Use premium unleaded gasoline with an octane rating of 91 AKI or higher. Regular unleaded gasoline with an octane rating of 87 AKI may be used if necessary. For optimum engine performance and driveability, it is recommended that you use premium grade unleaded gasoline. Fuel octane rating: 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" section in this manual. Fuel capacity: 16.9 US gal (64 liters, 14.1 Imp gal) Engine oil: Use only API classification SL with the words "ENERGY CONSERVING" and the New API certification mark (starburst mark) displayed on the container. Engine oil capacity: 2.5 liter models 4.2 US qt (4.0 liters, 3.5 Imp qt) 3.0 liter models 6.1 US qt (5.8 liters, 5.1 Imp qt) Cold tire pressure: See the label located under the driver's door latch.