2012 Subaru Impreza Owner's Manual - Page 420

12-4 Specifications & Fuel NOTE The engine is designed to operate using unleaded gasoline. Model Except STI STI Fuel requirement 91 AKI (95 RON) or higher*1 93 AKI (98 RON) or higher*2 Fuel tank capacity 16.9 US gal (64 liters, 14.1 Imp gal) *1: If unleaded gasoline with an octane rating of 91 AKI (95 RON) is not available, unleaded gasoline with an octane rating of 87 AKI (90 RON) or higher may be temporarily used. For details, refer to "Fuel" F7-3. *2: If unleaded gasoline with an octane rating of 93 AKI (98 RON) is not available, unleaded gasoline with an octane rating of 91 AKI (95 RON) may be used with no detriment to engine durability or driveability. For details, refer to "Fuel" F7-3.