Subaru Forester 2017 Owner's Manual page 633

Fuel:
Non-turbo models
Use only unleaded gasoline with an octane rating of 87 AKI
(90 RON) or higher.
Turbo models
Unleaded gasoline with an octane rating of 93 AKI (98 RON)
or higher is recommended. Unleaded gasoline with an octane
rating of 91 AKI (95 RON) or higher 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. If unleaded gasoline with an octane
rating of 91 AKI (95 RON) is not available, refer to Fuel
requirements 7-3.
Fuel octane rating:
RON
This octane rating is the Research Octane Number.
AKI
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).
Fuel capacity:
15.9 US gal (60 liters, 13.2 Imp gal)
GAS STATION REFERENCE
Use only the following oils.
. API classification SN with the words RESOURCE CON-
SERVING
. or ILSAC GF-5, which can be identified with the ILSAC
certification mark (Starburst mark)
For the complete viscosity requirements, refer to Engine oil
12-4.
Non-turbo models: 5.1 US qt (4.8 liters, 4.2 Imp qt)
Turbo models: 5.4 US qt (5.1 liters, 4.5 Imp qt)
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 the oil level gauge. For more details about
maintenance and service, refer to Engine oil
Refer to Tires
Engine oil:
Engine oil capacity:
Cold tire pressure:
12-10.
11-10.