2006 SUBARU IMPREZA WRX wheel torque

Starting and operating 7-13
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The driver’s control center differential al-
lows you to freely change the degree of
limitation of the differential action (limited
slip differential (LSD) torque) of your vehi-
cle ’s center differential.
By using the center differential control di-
al, you can set an initial LSD torque to
match the road surface conditions, driving
conditions and your driving style.
1) LSD torque
2) Traction torque
A) Initial LSD torque (adjustable)
B) Mechanical LSD torque
NOTE
If you rapidly depress and release the
accelerator pedal while driving at low
speed, you may hear a knocking sound
from the vicinity of the center differen-
tial and rear differential. This sound oc-
curs because of the structure of the
center differential. It does not indicate
a problem.
Auto mode
In the auto mode, the system estimates
the driving and road conditions using sig-
nals from the wheel speed sensor, throttle
position sensor, steering angle sensor
and brake switch, etc. According to the re-
sult, it electronically and automatically
controls the degree of limitation of the dif-
ferential action (LSD torque) to optimize
the differential action of the center differ-
ential. When the ignition switch is turned
ON, the “AUTO ” indicator light in the com-
bination meter comes on. The system can
be switched to a manual mode.
Manual mode
In the manual mode, you can use the cen-
ter differential control dial to adjust the ini-
In the event of failure of the driver
’s
control center differential, the “ ”
indicator light will flash. Have the
vehicle inspected by your SUBARU
dealer.
700378
LOCK1
2A
B
700123

Starting and operating 7-15
Turn the dial rearward to reduce the initial
LSD torque; when the white line reaches
the rearmost position, the initial LSD
torque will be minimum and the “ ” indi-
cator light will come on. Under this condi-
tion, only the Mechanical LSD torque will
limit the differential action.
NOTE
A higher initial LSD torque setting
gives the vehicle greater traction when
driving straight ahead but makes cor-
nering more difficult. Remember this
when adjusting the initial LSD torque.
In general, higher initial LSD torque
settings assist driving on slippery
roads and lower settings for non-slip-
pery roads. If you become stuck in
snow or mud, turning the center differ-
ential control dial to the frontmost po-
sition will help move the vehicle out.
(The “LOCK ” indicator will come on at
the frontmost position.)
During cornering or when making
turns (especially when getting into the
garage), the rotational difference be-
tween the front and rear wheels may
cause a braking effect accompanied by vibration and noise. This does not indi-
cate a problem. The phenomenon will
disappear when you turn the center dif-
ferential control dial to the rearmost
position (minimum initial LSD torque
position).
Use the center-differential indicator
light only as a rough indication of the
initial LSD torque.
If you operate the center differential
control dial while quickly accelerating
or turning a tight corner, you may feel
slight shocks. This is due to differential
action by the center differential and
does not indicate a problem.
Temporary release
When the driver stops the vehicle and
pulls the parking-brake lever after manual-
ly setting the initial LSD torque, the LSD
torque is temporarily minimized. However
the indicator in the combination meter
continues to show the driver ’s selected ini-
tial LSD torque. When the driver releases
the parking-brake lever, the initial LSD
torque set by the driver is restored.
Do not turn the control dial when
a wheel slippage occurs. Wait un-
til the wheelspin has been
brought under control.
700358
Under any of the following condi-
tions, turn the center differential
control dial to the rearmost posi-
tion to minimize the initial LSD
torque:
When a temporary spare tire is
installed
When your vehicle is towed
When the vehicle is stopped
with the manual mode selected

9-8 In case of emergency
13.Use the wheel nut wrench to securely
tighten the wheel nuts to the specified
torque, following the tightening order in
the illustration.
The torque for tightening the nuts is 58 to
72 lbf ∑ft (80 to 100 N ∑m, 8 to 10 kgf ∑m).
This torque is equivalent to applying ap-
proximately 88 to 110 lbs (40 to 50 kg) at
the top of the wheel nut wrench. Never
use your foot on the wheel nut wrench or
a pipe extension on the wrench because
you may exceed the specified torque.
Have the wheel nut torque checked at the
nearest automotive service facility. 14.Store the flat tire in the spare tire com-
partment.
Put the spacer and tighten the attaching
bolt firmly.
Also store the jack and wheel nut wrench
in their storage locations.After placing the jack in its storage loca-
tion, turn the jackscrew clockwise by hand
until it becomes too hard to turn. Then,
tighten it by an additional 1/4
– 1/3 of a
turn using a screwdriver or the jack han-
dle. Unless the jack is properly secured, it
may rattle while the vehicle is moving.
1
42
53
900056900012
900057
Never place a tire or tire changing
tools in the passenger compartment
after changing wheels. In a sudden
stop or collisions, loose equipment
could strike occupants and cause
injury. Store the tire and all tools in
the proper place.

11-34 Maintenance and service
placard and to have a speed symbol and
load index matching those shown on the
tire placard.
Using tires of a non-specified size detracts
from controllability, ride comfort, braking
performance, speedometer accuracy and
odometer accuracy. It also creates incor-
rect body-to-tire clearances and inappro-
priately changes the vehicle ’s ground
clearance.
All four tires must be the same in terms of
manufacturer, brand (tread pattern), con-
struction, and size. You are advised to re-
place the tires with new ones that are
identical to those fitted as standard equip-
ment.
For safe vehicle operation, SUBARU rec-
ommends replacing all four tires at the
same time.
Wheel replacement
When replacing wheels due, for example,
to damage, make sure the replacement
wheels match the specifications of the
wheels that are fitted as standard equip-
ment. Replacement wheels are available
from SUBARU dealers.
NOTE
When any of the wheels is removed
and replaced for tire rotation or to
change a flat tire, always check the
tightness of the wheel nuts after driv-
ing approximately 600 miles (1,000
km). If any nut is loose, tighten it to the
specified torque.
All four tires must be the same in
terms of manufacturer, brand
(tread pattern), construction, de-
gree of wear, speed symbol, load
index and size. Mixing tires of dif-
ferent types, sizes or degrees of
wear can result in damage to vehi-
cle ’s power train. Use of different
types or sizes of tires can also
dangerously reduce controllabili-
ty and braking performance and
can lead to an accident.
Use only radial tires. Do not use
radial tires together with belted
bias tires and/or bias-ply tires. Do-
ing so can dangerously reduce
controllability, resulting in an ac-
cident.
Use only those wheels that are
specified for your vehicle. Wheels
not meeting specifications could in-
terfere with brake caliper operation
and may cause the tires to rub
against the wheel well housing dur-
ing turns. The resulting loss of vehi-
cle control could lead to an acci-
dent.

Maintenance and service 11-35
Aluminum wheels
Aluminum wheels can be scratched and
damaged easily. Handle them carefully to
maintain their appearance, performance,
and safety.
When any of the wheels is removed and
replaced for tire rotation or to change a
flat, always check the tightness of the
wheel nuts after driving approximately 600
miles (1,000 km). If any nut is loose, tight-
en it to the specified torque.
Never apply oil to the threaded parts,
wheel nuts, or tapered surface of the
wheel.
Never let the wheel rub against sharp
protrusions or curbs.
Be sure to fit tire chains on uniformly
and completely around the tire, otherwise
the chains may scratch the wheel.
When wheel nuts, balance weights, or
the center cap is replaced, be sure to re-
place them with genuine SUBARU parts
designed for aluminum wheels.
Intercooler water spray
(WRX-STI)
Add water to the intercooler water spray
tank when the intercooler water spray
warning light in the combination meter
comes on. The warning light comes on
when the water in the tank has decreased
to approximately 0.4 liters (0.4 US qt, 0.4
Imp qt). The tank is located on the right-hand side
of the trunk.
NOTE
Use only pure water for refilling.
In cold weather (when you do not use
the intercooler water spray), keep the
tank half-empty in case the water freez-
es. A larger amount of water could
break the tank if it froze.
B00462
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Consumer information and Reporting safety defects 13-7
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asymmetrical tire that has a particu-
lar side that must always face out-
ward when mounting on a vehicle.
Accessory weight
The combined weight (in excess of
those standard items which may be
replaced) of floor mats, leather seats
and cross bars to the extent that these
items are available as factory-in-
stalled equipment (whether installed
or not).
Curb weight
The weight of a motor vehicle with
standard equipment including the
maximum capacity of fuel, oil, and
coolant and air conditioning.
Maximum loaded vehicle weight
The sum of curb weight, accessory
weight, vehicle capacity weight and
production options weight.
Normal occupant weight
150 lbs (68 kg) times the number of
occupants (3 occupants).
Occupant distribution
Distribution of occupants in a vehicle,
2 in front, 1 in rear seat.
Production options weight
The combined weight of those in-
stalled regular production options weighing over 5.1 lbs (2.3 kg) in ex-
cess of those standards items which
they replace, not previously consid-
ered in curb weight or accessory
weight.
Vehicle capacity weight
The total weight of cargo, luggage
and occupants that can be added to
the vehicle.
Vehicle maximum load on a tire
Load on an individual tire that is deter-
mined by distributing to each axle its
share of the maximum loaded vehicle
weight and dividing by two.
Vehicle normal load on a tire
Load on an individual tire that is deter-
mined by distributing to each axle its
share of the curb weight, accessory
weight, and normal occupant weight
and dividing by two.
Tire care – maintenance and
safety practices
Check on a daily basis that the tires
are free from serious damage, nails,
and stones. At the same time, check
the tires for abnormal wear.
Inspect the tire tread regularly and
replace the tires before their tread wear indicators become visible. When
a tire
’s tread wear indicator becomes
visible, the tire is worn beyond the ac-
ceptable limit and must be replaced
immediately. With a tire in this condi-
tion, driving at even low speeds in wet
weather can cause the vehicle to hy-
droplane. Possible resulting loss of
vehicle control can lead to an acci-
dent.
To maximize the life of each tire and
ensure that the tires wear uniformly, it
is best to rotate the tires every 7,500
miles (12,500 km). Rotating the tires
involves switching the front and rear
tires on the right-hand side of the ve-
hicle and similarly switching the front
and rear tires on the left-hand side of
the vehicle. (Each tire must be kept on
its original side of the vehicle.) Re-
place any damaged or unevenly worn
tire at the time of rotation. After tire ro-
tation, adjust the tire pressures and
make sure the wheel nuts are correct-
ly tightened. A tightening torque spec-
ification and a tightening sequence
specification for the wheel nuts can be
found “Flat tires ” section in chapter 9.