tire size SUBARU IMPREZA WRX STI 2012 Owners Manual

Black plate (49,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
system inoperative, which may
result in serious injury. Do not
use electrical test equipment on
any circuit related to the seatbelt
pretensioner and SRS airbag
systems. For required servicing
of the seatbelt pretensioner, con-
sult your nearest SUBARU deal-
er.
CAUTION
The front sub sensors are located
on both the right and left sides at the
front of the vehicle, and the SRS
airbag control module including the
impact sensors is located under the
center console. If you need service
or repair in those areas or near the
front seatbelt retractors, have the
work performed by your authorized
SUBARU dealer.NOTEIf the front part of the vehicle is
damaged in an accident to the extent
that the seatbelt pretensioner does not
operate, contact your SUBARU dealer
as soon as possible.
& Precautions against vehicle
modificationAlways consult your SUBARU dealer if
you want to install any accessory parts to
your vehicle.
CAUTION
Do not perform any of the following
modifications. Such modifications
can interfere with proper operation
of the seatbelt pretensioners.
. Attachment of any equipment
(bush bar, winches, snow plow,
skid plate, etc.) other than genu-
ine SUBARU accessory parts to
the front end.
. Modification of the suspension
system or front end structure.
. Installation of a tire of different
size and construction from the
tires specified on the vehicle
placard attached to the driver ’s
door pillar or specified for indivi-
dual vehicle models in this Own-
er ’s Manual.
Child restraint systemsInfants and small children should always
be placed in an infant or child restraint
system in the rear seat while riding in the
vehicle. You should use an infant or child
restraint system that meets Federal Motor
Vehicle Safety Standards or Canada
Motor Vehicle Safety Standards, is com-
patible with your vehicle and is appro-
priate for the child ’s age and size. All child
restraint systems are designed to be
secured in vehicle seats by lap belts or
the lap belt portion of a lap/shoulder belt
(except those described in “Installation of
child restraint systems by use of lower and
tether anchorages (LATCH) ”F 1-29).
Children could be endangered in an
accident if their child restraints are not
Seat, seatbelt and SRS airbags
1-21
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1

Black plate (86,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
1-58
Seat, seatbelt and SRS airbags
. Installation of additional electri-
cal/electronic equipment such as
a mobile two-way radio on or
near the SRS airbag system
components and/or wiring is not
advisable. This could interfere
with proper operation of the
SRS airbag system.
CAUTION
Do not perform any of the following
modifications. Such modifications
can interfere with proper operation
of the SRS airbag system.
. Attachment of any equipment
(bush bar, winches, snow plow,
skid plate, etc.) other than genu-
ine SUBARU accessory parts to
the front end.
. Modification of the suspension
system or front end structure.
. Installation of a tire of different
size and construction from the
tires specified on the vehicle
placard attached to the driver ’s
door pillar or specified for indivi-
dual vehicle models in this Own-
er ’s Manual.
. Attachment of any equipment
(side steps or side sill protectors, etc.) other than genuine SUBARU
accessory parts to the side body.
Always consult your SUBARU dealer if
you want to install any accessory parts on
your vehicle.

Black plate (134,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
3-16
Instruments and controls
The CHECK ENGINE warning light may
stop blinking and illuminate steadily after
several driving trips. You should have your
vehicle checked by an authorized
SUBARU dealer immediately.&
Charge warning light
If this light illuminates when the engine is
running, it may indicate that the charging
system is not working properly.
If the light illuminates while driving or does
not turn off after the engine starts, stop the
engine at the first safe opportunity and
check the alternator belt. If the belt is
loose, broken or if the belt is in good
condition but the light remains illuminated,
contact your nearest SUBARU dealer
immediately.&
Oil pressure warning
light
If this light illuminates when the engine is
running, it may indicate that the engine oil
pressure is low and the lubricating system
is not working properly.
If the light illuminates while driving or does
not turn off after the engine starts, stop the
engine at the first safe opportunity and
check the engine oil level. If the oil level is
low, add oil immediately. If the engine oil is
at the proper level but the light remains illuminated, contact your nearest
SUBARU dealer immediately.
For details about checking the engine oil
level or adding the engine oil, refer to
“Engine oil
”F 11-8.
CAUTION
Do not operate the engine with the
oil pressure warning light illumi-
nated. This may cause serious en-
gine damage.&
Rear differential oil
temperature warning
light (STI)
CAUTION
Reduce vehicle speed and park the
vehicle in a safe place as soon as
possible if the R.DIFF TEMP light
illuminates. Continued driving with
this light illuminated can damage
the rear differential and other parts
of the powertrain.
If this light illuminates when the engine is
running, it may indicate that the rear
differential oil temperature is too hot.
At this time, the driver ’s control center
differential will automatically cancel the current torque-distribution ratio setting and
adopt its minimum ratio.
If the light illuminates while driving, reduce
vehicle speed and stop the vehicle at the
nearest safe place. Park the vehicle for
several minutes. After the light turns off,
you can start driving.
If the light does not turn off, contact the
nearest SUBARU dealer for service.
NOTE.
If the tire pressures are not correct
and/or the tires are not all the same
size and brand, the rear differential will
be heavily loaded when the vehicle is
driven, resulting in an abnormally high
oil temperature.
. The rear differential oil will deterio-
rate if its temperature increases en-
ough for the rear differential oil tem-
perature warning light to illuminate. It is
advisable to have the rear differential
oil replaced as soon as possible.&
Low tire pressure
warning light (U.S.-spec.
models)
When the ignition switch is turned to the
“ON ”position, the low tire pressure warn-
ing light will illuminate for approximately 2
seconds to check that the tire pressure

Black plate (135,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
monitoring system (TPMS) is functioning
properly. If there is no problem and all tires
are properly inflated, the light will turn off.
Each tire, including the spare (if provided),
should be checked monthly when cold
and inflated to the inflation pressure
recommended by the vehicle manufac-
turer on the vehicle placard or tire inflation
pressure label. (If your vehicle has tires of
a different size than the size indicated on
the vehicle placard or tire inflation pres-
sure label, you should determine the
proper tire inflation pressure for those
tires.)
As an added safety feature, your vehicle
has been equipped with a tire pressure
monitoring system (TPMS) that illuminates
a low tire pressure telltale when one or
more of your tires is significantly under-
inflated. Accordingly, when the low tire
pressure telltale illuminates, you should
stop and check your tires as soon as
possible, and inflate them to the proper
pressure. Driving on a significantly under-
inflated tire causes the tire to overheat and
can lead to tire failure. Under-inflation also
reduces fuel efficiency and tire tread life,
and may affect the vehicle’ s handling and
stopping ability.
Please note that the TPMS is not a
substitute for proper tire maintenance,
and it is the driver ’s responsibility to maintain correct tire pressure, even if
under-inflation has not reached the level
to trigger illumination of the TPMS low tire
pressure telltale.
Your vehicle has also been equipped with
a TPMS malfunction indicator to indicate
when the system is not operating properly.
The TPMS malfunction indicator is com-
bined with the low tire pressure telltale.
When the system detects a malfunction,
the telltale will flash for approximately one
minute and then remain continuously
illuminated. This sequence will continue
upon subsequent vehicle start-ups as long
as the malfunction exists. When the
malfunction indicator is illuminated, the
system may not be able to detect or signal
low tire pressure as intended. TPMS
malfunctions may occur for a variety of
reasons, including the installation of re-
placement or alternate tires or wheels on
the vehicle that prevent the TPMS from
functioning properly. Always check the
TPMS malfunction telltale after replacing
one or more tires or wheels on your
vehicle to ensure that the replacement or
alternate tires and wheels allow the TPMS
to continue to function properly.
Should the warning light illuminate stea-
dily after blinking for approximately one
minute, have the system inspected by
your nearest SUBARU dealer as soon as
possible.
WARNING
If this light does not illuminate
briefly after the ignition switch is
turned ON or the light illuminates
steadily after blinking for approxi-
mately one minute, you should have
your Tire Pressure Monitoring Sys-
tem checked at a SUBARU dealer as
soon as possible.
If this light illuminates while driving,
never brake suddenly and keep
driving straight ahead while gradu-
ally reducing speed. Then slowly
pull off the road to a safe place.
Otherwise an accident involving
serious vehicle damage and serious
personal injury could occur.
If this light still illuminates while
driving after adjusting the tire pres-
sure, a tire may have significant
damage and a fast leak that causes
the tire to lose air rapidly. If you have
a flat tire, replace it with a spare tire
as soon as possible.
When a spare tire is mounted or a
wheel rim is replaced without the
original pressure sensor/transmitter
being transferred, the Low tire pres-
sure warning light will illuminate
Instruments and controls
3-17
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CONTINUED –
3

Black plate (136,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
3-18
Instruments and controls
steadily after blinking for approxi-
mately one minute. This indicates
the TPMS is unable to monitor all
four road wheels. Contact your
SUBARU dealer as soon as possible
for tire and sensor replacement and/
or system resetting.
If the light illuminates steadily after
blinking for approximately one min-
ute, promptly contact a SUBARU
dealer to have the system inspected.
CAUTION
The tire pressure monitoring system
is NOT a substitute for manually
checking tire pressure. The tire
pressure should be checked peri-
odically (at least monthly) using a
tire gauge. After any change to tire
pressure(s), the tire pressure mon-
itoring system will not re-check tire
inflation pressures until the vehicle
is first driven more than 20 mph (32
km/h). After adjusting the tire pres-
sures, increase the vehicle speed to
at least 20 mph (32 km/h) to start the
TPMS re-checking of the tire infla-
tion pressures. If the tire pressures
are now above the severe low
pressure threshold, the low tire
pressure warning light should turn off a few minutes later. Therefore, be
sure to install the specified size for
the front and rear tires.
&
ABS warning light
CAUTION
.
If any of the following conditions
occur, we recommend that you
have the ABS system repaired at
the first available opportunity by
your SUBARU dealer.
– The warning light does not
illuminate when the ignition
switch is turned to the “ON ”
position.
– The warning light illuminates
when the ignition switch is
turned to the “ON ”position,
but it does not turn off even
when the vehicle speed ex-
ceeds approximately 8 mph
(12 km/h).
– The warning light illuminates
during driving.
. When the warning light is on (and
the brake system warning light is
off), the ABS function shuts
down. However, the conventional
brake system continues to oper- ate normally.
With a vehicle equipped with an EBD
system, the ABS warning light illuminates
together with the brake system warning
light if the EBD system malfunctions. For
further details of the EBD system mal-
function warning, refer to “Electronic
Brake Force Distribution (EBD) system
warning ”F 3-19.
NOTEIf the warning light behavior is as
described in the following conditions,
the ABS system may be considered
normal.
. The warning light illuminates right
after the engine is started but turns off
immediately, remaining off.
. The warning light remains illumi-
nated after the engine has been started,
but it turns off when the vehicle speed
reaches approximately 8 mph (12
km/h).
. The warning light illuminates during
driving, but it turns off immediately and
remains off.
When driving with an insufficient battery
voltage such as when the engine is jump
started, the ABS warning light may illumi-
nate. This is due to the low battery voltage
and does not indicate a malfunction.

Black plate (274,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
7-24
Starting and operating
Limited slip differential (LSD)
(STI)The LSD provides optimum distribution of
power according to the difference in
revolutions between the right and left
wheels that may be caused by certain
driving conditions, thereby improving driv-
ing stability on snow-covered, muddy or
other slippery roads or when high speed
driving.
CAUTION
. Never start the engine while a tire
on one side is jacked up, as the
vehicle may move.
. If one tire is spinning in mud,
avoid continued spinning at high
speed as this could adversely
affect the LSD.
. If you use a temporary spare tire
to replace a flat tire, be sure to
use the original temporary spare
tire stored in the vehicle. Using
other sizes will adversely affect
the LSD.
Power steeringThe power steering system operates only
when the engine is running.
If you lose power steering assist because
the engine stops or the system fails to
function, you can steer but it will take
much more effort.
CAUTION
Do not hold the steering wheel at the
fully locked position left or right for
more than 5 seconds. This may
damage the power steering pump.NOTERight after the engine has been started
and before it has warmed up, you may
hear a noise coming from areas adja-
cent to the power steering pump which
is located at the right-front area of the
engine compartment. This noise is
normal. It does not indicate power
steering system trouble.
Braking& Braking tips
WARNING
Never rest your foot on the brake
pedal while driving. This can cause
dangerous overheating of the
brakes and needless wear on the
brake pads and linings.
! When the brakes get wet
When driving in rain or after washing the
vehicle, the brakes may get wet. As a
result, brake stopping distance will be
longer. To dry the brakes, drive the vehicle
at a safe speed while lightly depressing
the brake pedal to heat up the brakes.
! Use of engine braking
Remember to make use of engine braking
in addition to foot braking. When descend-
ing a grade, if only the foot brake is used,
the brakes may start working improperly
because of brake fluid overheating,
caused by overheated brake pads. To
help prevent this, shift into a lower gear to
get stronger engine braking.
! Braking when a tire is punctured
Do not depress the brake pedal suddenly
when a tire is punctured. This could cause

Black plate (278,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
7-28
Starting and operating
Vehicle Dynamics Control
system
WARNING
Always use the utmost care in
driving –overconfidence because
you are driving with a Vehicle Dy-
namics Control system equipped
vehicle could easily lead to a ser-
ious accident.
CAUTION
. Even if your vehicle is equipped
with Vehicle Dynamics Control
system, winter tires should be
used when driving on snow-cov-
ered or icy roads; in addition,
vehicle speed should be reduced
considerably. Simply having a
Vehicle Dynamics Control sys-
tem does not guarantee that the
vehicle will be able to avoid
accidents in any situation.
. Activation of the Vehicle Dy-
namics Control system is an
indication that the road being
travelled on has a slippery sur-
face; since having Vehicle Dy-
namics Control is no guarantee that full vehicle control will be
maintained at all times and under
all conditions, its activation
should be seen as a sign that
the speed of the vehicle should
be reduced considerably.
. Whenever suspension compo-
nents, steering components, or
an axle are removed from a
vehicle, have an inspection of
that system performed by an
authorized SUBARU dealer.
. The following precautions should
be observed in order to ensure
that the Vehicle Dynamics Con-
trol system is operating properly:
– All four wheels should be
fitted with tires of the same
size, type, and brand. Further-
more, the amount of wear
should be the same for all
four tires.
– Keep the tire pressure at the
proper level as shown on the
vehicle placard attached to
the driver ’s side door pillar.
– Use only the specified tem-
porary spare tire to replace a
flat tire. With a temporary
spare tire, the effectiveness
of the Vehicle Dynamics Con- trol system is reduced and
this should be taken into ac-
count when driving the vehi-
cle in such a condition.
. If non-matching tires are used,
the Vehicle Dynamics Control
system may not operate cor-
rectly.
. The Vehicle Dynamics Control
system helps prevent unstable
vehicle motion such as skidding
using control of the brakes and
engine power. Do not turn off the
Vehicle Dynamics Control sys-
tem unless it is absolutely ne-
cessary. If you must turn off the
Vehicle Dynamics Control sys-
tem, drive very carefully based
on the road surface condition.
In the event of wheelspin and/or skidding
on a slippery road surface and/or during
cornering and/or an evasive maneuver,
the Vehicle Dynamics Control system
adjusts the engine ’s output and the
wheels ’respective braking forces to help
maintain traction and directional control.
. Traction Control Function
The traction control function is designed to
prevent spinning of the driving wheels on
slippery road surfaces, thereby helping to
maintain traction and directional control.

Black plate (296,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
8-4
Driving tips
Periodic inspectionsTo keep your vehicle in the best condition
at all times, always have the recom-
mended maintenance services listed in
the maintenance schedule in the “War-
ranty and Maintenance Booklet ”per-
formed at the specified time or mileage
intervals.
Driving in foreign countriesWhen planning to use your vehicle in
another country:
. Confirm the availability of the correct
fuel. Refer to “Fuel requirements ”F 7-3.
. Comply with all regulations and re-
quirements of each country.
Driving tips for AWD models
WARNING
. Always maintain a safe driving
speed according to the road and
weather conditions in order to
avoid having an accident on a
sharp turn, during sudden brak-
ing or under other similar condi-
tions.
. Always use the utmost care in
driving –overconfidence be-
cause you are driving an All-
Wheel Drive vehicle could easily
lead to a serious accident.
. When replacing a tire, you must
use a tire that is of the same size,
circumference, construction,
brand (tread pattern), speed sym-
bol and load index as the original
tires listed on the tire placard.
Using tires of other sizes, cir-
cumferences or constructions
may result in severe mechanical
damage to the drive train of your
vehicle and may affect ride,
handling, braking, speedometer/
odometer calibration, and clear-
ance between the body and tires.
It also may be dangerous and

Black plate (297,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
lead to loss of vehicle control.
. You must install four tires that are
of the same size, circumferences,
construction, manufacturer,
brand (tread pattern), degree of
wear, speed symbol and load
index. Mixing tires of other sizes,
circumferences or constructions
may result in severe mechanical
damage to the drive train of your
vehicle and may affect ride,
handling, braking and speed-
ometer/odometer calibration. It
also may be dangerous and lead
to loss of vehicle control.
CAUTION
If you use a temporary spare tire to
replace a flat tire, be sure to use the
original temporary spare tire stored
in the vehicle. Using other sizes may
result in severe mechanical damage
to the drive train of your vehicle.
All-Wheel Drive distributes the engine
power to all four wheels. AWD models
provide better traction when driving on
slippery, wet or snow-covered roads and
when moving out of mud, dirt and sand.
By shifting power between the front and
rear wheels, SUBARU AWD can also
provide added traction during acceleration
and added engine braking force during
deceleration.
Therefore, your SUBARU AWD vehicle
may handle differently than an ordinary
two wheel drive vehicle and it contains
some features unique to AWD. For safety
purposes as well as to avoid damaging
the AWD system, you should keep the
following tips in mind.
. An AWD model is better able to climb
steeper roads under snowy or slippery conditions than a two wheel drive vehicle.
There is little difference in handling,
however, during extremely sharp turns or
sudden braking. Therefore, when driving
down a slope or turning corners, be sure
to reduce your speed and maintain an
ample distance from other vehicles.
.
Always check the cold tire pressure
before starting to drive. The recom-
mended tire pressure is provided on the
tire placard, which is located under the
door latch on the driver ’s side.
. Frequent driving of an AWD vehicle in
hard driving conditions such as steep hills
or dusty roads will necessitate more
frequent replacement of engine oil, brake
fluid and transmission oil than that speci-
fied in the “Warranty and Maintenance
Booklet ”.
. There are some precautions that you
must observe when towing your vehicle.
For detailed information, refer to “Towing”
F 9-12.
Driving tips
8-5
8

Black plate (300,1)
北米Model "A1130BE-A" EDITED: 2011/ 6/ 7
8-8
Driving tips
vehicle control.
CAUTION
Avoid prolonged continuous driving
in snowstorms. Snow will enter the
engine ’s intake system and may
hinder the airflow, which could re-
sult in engine shutdown or even
breakdown.
! Wiper operation when snowing
Before driving in cold weather, make sure
the wiper blades are not frozen to the
windshield or rear window.
If the front wiper blades are frozen to the
windshield, use the defroster with the
airflow control dial in the “
”position
and the temperature control dial set for
maximum warmth until the wiper blades
are completely thawed out. For details,
refer to the following section.
. For the manual climate control system,
refer to “Defrosting or defogging the
windshield ”F 4-5.
. For the automatic climate control sys-
tem, refer to “Control panel ”F 4-8.
If your vehicle is equipped with a wind-
shield wiper deicer, it is helpful to thaw the
windshield wiper blades. Refer to “Defog-ger and deicer
”F 3-45.
If the rear wiper blade is frozen to the rear
window, use the rear window defogger.
Refer to “Defogger and deicer ”F 3-45.
When driving in snow, if frozen snow starts
to stick on the surface of the windshield
despite wiper operation, use the defroster
with the airflow control dial in “
”and the
temperature control dial set for maximum
warmth. After the windshield gets warmed
enough to melt the frozen snow on it,
wash it away using the windshield washer.
Refer to “Washer”F 3-36.
Snow stuck on the wiper arm prevents the
wiper from working effectively. If snow is
stuck on the wiper arm, pull off the road to
a safe place, then remove it. If you stop
the vehicle at road side, use the hazard
warning flasher to alert other drivers.
We recommend use of non-freezing type
wiper blades (winter blades) during the
seasons you could have snow and freez-
ing temperatures. Blades of this type give
superior wiping performance in snowy
conditions. Be sure to use blades that
are suitable for your vehicle.
CAUTION
During high-speed driving, non-
freezing type wiper blades may not perform as well as standard wiper
blades. If this happens, reduce the
vehicle speed.
NOTEWhen the season requiring non-freez-
ing type wiper blades is over, replace
them with standard wiper blades.&
Corrosion protectionRefer to “Corrosion protection ”F 10-4.& Snow tires
WARNING
. When replacing original tires with
winter (snow) tires, make sure
you use only tires of the same
size, circumference, construc-
tion, brand (tread pattern), speed
symbol and load index as the
original tires listed on the tire
placard. Using tires of other sizes
or constructions may affect
speedometer/odometer calibra-
tion and clearance between the
body and tires. It also may be
dangerous and lead to loss of
vehicle control.