2006 Subaru Impreza Owner's Manual - Page 365

Fuel: GAS STATION REFERENCE 2.5-liter non-turbo models Use only unleaded gasoline with an octane rating of 87 AKI or higher. of 93 AKI or higher. WRX Use premium unleaded gasoline with an octane rating of 91 AKI or higher. If premium unleaded gasoline with an octane rating of 91 AKI is not available, regular unleaded gasoline with octane rating of 87 AKI or higher may be temporarily used. For optimum engine performance and driveability, it is required that you use premium grade unleaded gasoline with an octane rating of 91 AKI or higher. WRX-STI Use super-premium unleaded gasoline with an octane rating of 93 AKI or higher. If super-premium unleaded gasoline with an octane rating of 93 AKI is not available, premium unleaded gasoline with octane rating of 91 AKI or higher may be temporarily used. For optimum engine performance and driveability, it is required that you use super-premium grade unleaded gasoline with an 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 octane rating Fuel capacity: Engine oil: 15.9 US gal (60 liters, 13.2 Imp gal) Use only API classification SM with the words “ENERGY CONSERVING” and the ILSAC certification mark (starburst mark) displayed on the container. Engine oil capacity: 4.2 US qt (4.0 liters, 3.5 Imp qt) Cold tire pressure: Tire size Item Wheel size Pressure 2.5i, OUTBACK SPORT P205/55R16 89V 16  61/2 JJ 33 psi (230 kPa, 2.3 kgf/cm2) 30 psi (210 kPa, 2.1 kgf/cm2) 215/45R17 91W 33 psi (230 kPa, 2.3 kgf/cm2) 32 psi (220 kPa, 2.2 kgf/cm2) 60 psi (420 kPa, 4.2 kgf/cm2) 17  7 JJ WRX 225/45R17 90W 36 psi (250 kPa, 2.5 kgf/cm2) 30 psi (210 kPa, 2.1 kgf/cm2) T135/70 D17 17  8 JJ WRX-STI Front Rear Temporary spare Size tire Pressure T135/70 D16