Subaru WRX & WRX STI Manuals 2011 Impreza WRX & WRX STI Owner's Manual | Page 451

& Fuel:

GAS STATION REFERENCE
& Fuel octane rating:

! Non-turbo models
Use only unleaded gasoline with an octane rating of 87 AKI
(90 RON) or higher.

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.

! Turbo models except STI
Use premium unleaded gasoline with an octane rating of 91
AKI (95 RON) or higher. If premium unleaded gasoline with an
octane rating of 91 AKI (95 RON) is not available, regular
unleaded gasoline with octane rating of 87 AKI (90 RON) 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 (95
RON) or higher.

& 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.

For the complete viscosity requirements, refer to the following
sections.
. “Recommended grade and viscosity” F11-13
. “Recommended grade and viscosity under severe driving
conditions” F11-14

16.9 US gal (64 liters, 14.1 Imp gal)

& 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”

& Engine oil capacity:
4.2 US qt (4.0 liters, 3.5 Imp qt)

& Cold tire pressure:
Refer to “Tires” F12-5.