2011 SUBARU IMPREZA WRX octane

&Abbreviation list
You will find several abbreviations in this
manual. The meanings of the abbrevia-
tions are shown in the following list.
Abbreviation Meaning
A/C Air conditioner A/ELR Automatic/Emergency locking retractor
ABS Anti-lock brake system
AKI Anti knock index
ALR Automatic locking retractor
AT Automatic transmission
ATF Automatic transmission fluid
AWD All-wheel drive DCCD Driver
’s control center differ-
ential
DRL Daytime running lightEBD Electronic brake force distri- bution
ELR Emergency locking retractor
FWD Front-wheel drive
GAW Gross axle weight
GAWR Gross axle weight rating
GVW Gross vehicle weight
GVWR Gross vehicle weight rating
HID High intensity discharge Abbreviation Meaning
INT Intermittent
LATCH Lower anchors and tethers for
children
LED Light emitting diode
LSD Limited slip differential
MIL Malfunction indicator lamp MMT Methylcyclopentadienyl man-
ganese tricarbonyl
MT Manual transmission
OBD On-board diagnostics
RON Research octane number
SI-DRIVE SUBARU Intelligent Drive SRS Supplemental restraint sys- tem
TIN Tire identification number TPMS Tire pressure monitoring sys- tem
VDC Vehicle dynamics control Vehicle symbols
There are some of the symbols you may
see on your vehicle.
For warning and indicator lights, refer to “
Warning and indicator lights ”F 24.
Mark Name
WARNING
CAUTION
Power door lock (turbo mod- els)
Power door unlock (turbo models)
Power door lock and unlock
(non-turbo models)
Power window with automatic
open (all models) and close (if
equipped) function
Passengers ’windows lock
and unlock
Fuel 3
– CONTINUED –

Fuel
CAUTION
Use of a fuel which is low in quality
or use of an inappropriate fuel
additive may cause engine damage.
& Fuel requirements
! Non-turbo models
The engine is designed to operate using
unleaded gasoline with an octane rating
of 87 AKI (90 RON) or higher .
! Turbo models
! Except STI
The engine is designed to operate usingpremium unleaded gasoline with an
octane rating of 91 AKI (95 RON) or
higher . If premium unleaded gasoline is
not available, regular unleaded gasoline
with an octane rating of 87 AKI (90 RON)
or higher may be temporarily used. For
optimum engine performance and drive-
ability, it is required that you use premium
grade unleaded gasoline. NOTE
Be sure to use premium unleaded
gasoline of 91 AKI (95 RON) or higher. If other gasoline (lower than 91 AKI (95
RON)) is used, knocking, reduced out-
put and poor accelerator response willresult. !
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 driveabil-
ity. However, you may notice a slight
decrease in maximum engine perfor-
mance while using 91 AKI (95 RON) fuel.
Use of 91 AKI (95 RON) fuel will not affect
your warranty coverage. ! 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).
Using a gasoline with a lower octane
rating can cause persistent and heavy
knocking, which can damage the engine.
Do not be concerned if your vehicle
sometimes knocks lightly when you drive
up a hill or when you accelerate. Contact
your SUBARU dealer if you use a fuel with
the specified octane rating and your vehicle knocks heavily or persistently. !
Unleaded gasoline
The neck of the fuel filler pipe is designed
to accept only an unleaded gasoline filler
nozzle. Under no circumstances should
leaded gasoline be used because it will
damage the emission control system and
may impair driveability and fuel economy. ! Gasoline for California-certified LEV
If your vehicle was certified to California ’s
low emission vehicle (LEV) standards as
indicated on the underhood tune-up label,
it is designed to optimize engine and
emission performance with gasoline that
meets the clean burning low-sulfur Cali-
fornia gasoline specifications. If you live in
any other state than California, your
vehicle will operate on gasoline meeting
Federal specifications. Gasoline sold out-
side California is permitted to have higher
sulfur levels, which may affect the perfor-
mance of your vehicle ’s catalytic converter
and may produce a sulfur exhaust odor or
smell. SUBARU recommends that you try
a different brand of unleaded gasoline
having lower sulfur to determine if the
problem is fuel related before returning
your vehicle to an authorized dealer forservice. Starting and operating
7-3
– CONTINUED –

7-4Starting and operating
!MMT
Some gasoline contains an octane-en-
hancing additive called MMT (Methylcy-
clopentadienyl Manganese Tricarbonyl). If
you use such fuels, your emission control
system performance may deteriorate and
the CHECK ENGINE warning light/Mal-
function indicator lamp may turn on. If this
happens, return to your authorized
SUBARU Dealer for service. If it is
determined that the condition is caused
by the type of fuel used, repairs may not
be covered by your warranty. ! Gasoline for cleaner air
Your use of gasoline with detergent
additives will help prevent deposits from
forming in your engine and fuel system.
This helps keep your engine in tune and
your emission control system working
properly, and is a way of doing your part
for cleaner air. If you continuously use a
high quality fuel with the proper detergent
and other additives, you should never
need to add any fuel system cleaning
agents to your fuel tank.
Many gasolines are now blended with
materials called oxygenates. Use of these
fuels can also help keep the air cleaner.
Oxygenated blend fuels, such as MTBE
(Methyl Tertiary Butyl ether) or ethanol
(ethyl or grain alcohol) may be used in your vehicle, but should contain no more
than 15% MTBE or 10% ethanol for the
proper operation of your SUBARU.
In addition, some gasoline suppliers are
now producing reformulated gasolines,
which are designed to reduce vehicle
emissions. SUBARU approves the use of
reformulated gasoline.
If you are not sure what the fuel contains,
you should ask your service station
operators if their gasolines contain deter-
gents and oxygenates and if they have
been reformulated to reduce vehicle emis-sions.
As additional guidance, only use fuels
suited for your vehicle as explained in the
following description. .
Fuel should be unleaded and have an
octane rating no lower than that specified
in this manual. . Methanol (methyl or wood alcohol) is
sometimes mixed with unleaded gasoline.
Methanol can be used in your vehicle
ONLY if it does not exceed 5% of the fuel
mixture ANDif it is accompanied by
sufficient quantities of the proper cosol-
vents and corrosion inhibitors required to
prevent damage to the fuel system. Do not
use fuel containing methanol EXCEPT
under these conditions. .
If undesirable driveability problems are
experienced and you suspect they may be
fuel related, try a different brand of gaso-
line before seeking service at your
SUBARU dealer. . Fuel system damage or driveability
problems which result from the use of
improper fuel are not covered under the
SUBARU Limited Warranty.
CAUTION
Do not let fuel spill on the exterior
surfaces of the vehicle. Because
fuel may damage the paint, be sure
to wipe off any spilled fuel quickly.
Paint damage caused by spilled fuel
is not covered under the SUBARU
Limited Warranty.
& Fuel filler lid and cap
! Refueling
Only one person should be involved in
refueling. Do not allow others to approach
the area of the vehicle near the fuel filler
pipe while refueling is in progress.
Be sure to observe any other precautions
that are posted at the service station.

12-4Specifications
&Fuel
NOTE
The engine is designed to operate using unleaded gasoline.
Model Fuel requirement Fuel tank capacities
Non-turbo 87 AKI (90 RON) or higher
16.9 US gal (64 liters, 14.1 Imp gal)
Turbo Except STI 91 AKI (95 RON) or higher*
1
STI
93 AKI (98 RON) or higher*2
*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 ”F 7-3.
*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 ”F 7-3.

GAS STATION REFERENCE
& Fuel:
! Non-turbo models
Use only unleaded gasoline with an octane rating of 87 AKI
(90 RON) or higher .
! 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 perfor-
mance and driveability, it is required that you use premium
grade unleaded gasoline with an octane rating of 91 AKI (95
RON) or higher. ! 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 warrantycoverage. &
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 octane rating ”F 7-3.
& Fuel capacity:
16.9 US gal (64 liters, 14.1 Imp gal) & Engine oil:
Use SUBARU approved motor oil or equivalent.
For the details, refer to “Engine oil ”F 12-5.
& Engine oil capacity:
4.4 US qt (4.2 liters, 3.7 Imp qt) & Cold tire pressure:
Refer to “Tires ”F 12-11.