2003 SUBARU IMPREZA tires

In case of emergency
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Wagon
1) Jack
2) Jack handle 3) Spare tire
The jack handle is stored under the spare tire cover.
For how to use the jack, refer to “Flat tires ”.

11
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Maintenance schedule 11-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance precautions 11-3 . . . . . . . . . . . . . . . . . . . . . . . .
Engine hood 11-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine compartment overview 11-8 . . . . . . . . . . . . . . . . .
2.5 liter model 11-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.0 liter (Turbo) model 11-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine oil 11-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the oil level 11-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing the oil and oil filter 11-11 . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-13 . . . . . . . . . . .
Recommended grade and viscosity under
severe driving conditions 11-15 . . . . . . . . . . . . . . . . . . . . . .
Synthetic oil 11-15
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling system 11-15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling fan, hose and connections 11-16 . . . . . . . . . . . .
Engine coolant 11-16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air cleaner element 11-20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing the air cleaner element 11-20 . . . . . . . . . . . . . .
Spark plugs 11-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended spark plugs 11-24 . . . . . . . . . . . . . . . . . . . . .
Drive belts 11-24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual transmission oil 11-25 . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the oil level 11-25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-26 . . . . . . . . . . .
Automatic transmission fluid 11-27 . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-27 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended fluid 11-29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Front differential gear oil (AT vehicles) 11-29
. . . . .
Checking the oil level 11-29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-30 . . . . . . . . . . .
Rear differential gear oil 11-31 . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the gear oil level 11-31 . . . . . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-32 . . . . . . . . . . .
Power steering fluid 11-32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-32 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended fluid 11-33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake fluid 11-34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-34 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended brake fluid 11-34 . . . . . . . . . . . . . . . . . . . . . . .
Clutch fluid (MT vehicles) 11-35 . . . . . . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-35 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended clutch fluid 11-36 . . . . . . . . . . . . . . . . . . . . . .
Brake booster 11-36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake pedal 11-37 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the brake pedal free play 11-37 . . . . . . . . . . . .
Checking the brake pedal reserve distance 11-37 . .
Clutch pedal (MT vehicles) 11-38 . . . . . . . . . . . . . . . . . . . . . .
Checking the clutch function 11-38 . . . . . . . . . . . . . . . . . . . .
Checking the clutch pedal free play 11-38 . . . . . . . . . . .
Replacement of brake pad and lining 11-39 . . . . . . . .
Breaking-in of new brake pads and linings 11-39 . . .
Parking brake stroke 11-40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tires and wheels 11-41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Types of tires 11-41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance and service

Maintenance and service
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Tires and wheels Types of tires
You should be familiar with type of tires present on your vehicle.
All season tires
The factory-installed tires on your new vehicle are all
season tires.
All season tires are designed to provide an ade-
quate measure of traction, handling and braking
performance in year-round driving including snowy
and icy road conditions. However all season tires do
not offer as much traction performance as winter
(snow) tires in heavy or loose snow or on icy roads.
All season tires are identified by “ALL SEASON ”
and/or “M+S” (Mud & Snow) on the tire sidewall.
Summer tires
The optional, dealer-installed, 17-inch tires recom-
mended for the WRX are summer tires.
Summer tires are high-speed capability tires best
suited for highway driving under dry conditions.
Summer tires are inadequate for driving on slippery
roads such as on snow-covered or icy roads.
If you drive your vehicle on snow-covered or icy
roads, we strongly recommend the use of winter (snow) tires.
When installing winter tires, be sure to replace all
four tires.
Winter (snow) tires
Winter tires are best suited for driving on snow-cov-
ered and icy roads. However winter tires do not per-
form as well as summer tires and all season tires on
roads other than snow-covered and icy roads.
Tire inspection
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.
Contact your SUBARU dealer immediately if you find
any problem. NOTE When the wheels and tires strike curbs or are
subjected to harsh treatment as when the vehicle is driven on a rough surface, they can suffer
damage that cannot be seen with the naked eye.This type of damage does not become evident
until time has passed. Try not to drive over curbs, potholes or on other rough surfaces. If
doing so is unavoidable, keep the vehicle ’s
speed down to a walking pace or less, and ap-

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proach the curbs as squarely as possible. Also,
make sure the tires are not pressed against thecurb when you park the vehicle.If you feel unusual vibration while driving or
find it difficult to steer the vehicle in a straight
line, one of the tires and/or wheels may be dam- aged. Drive slowly to the nearest authorized
SUBARU dealer and have the vehicle inspected. Tire pressures and wear
Maintaining the correct tire pressures helps to maxi-
mize the tires ’ service lives and is essential for good
running performance. Check and, if necessary, ad-
just the pressure of each tire (including the spare) at least once a month (for example, during a fuel stop)
and before any long journey.
Check the tire pressures when the tires are cold.
Use a pressure gauge to adjust the tire pressures to
the values shown on the tire placard. The tire plac-
ard is located on the door pillar on the driver ’s side.
Driving even a short distance warms up the tires
and increases the tire pressures. Also, the tire pres-
sures are affected by the ambient temperature. It is
best to check tire pressure outdoors before driving the vehicle.
When a tire becomes warm, the air inside it ex-
pands, causing the tire pressure to increase. Be
careful not to mistakenly release air from a warm tire
to reduce its pressure.

Maintenance and service
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NOTE The air pressure in a tire increases by approxi-
mately 4.3 psi (30 kPa, 0.3 kg/cm 2
) when the tire
becomes warm. The tires are considered cold when the vehicle
has been parked for at least three hours or hasbeen driven less than one mile (1.6 km).
WARNING
Do not let air out of warm tires to adjust
pressrue. Doing so will result in low tire pres- sure.
Incorrect tire pressures detract from controllability
and ride comfort, and they cause the tires to wear
abnormally.
Correct tire pressure (tread worn evenly)
Roadholding is good, and steering is responsive.
Rolling resistance is low, so fuel consumption is
also lower.

Maintenance and service
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WARNING
Driving at high speeds with excessively low tire pressures can cause the tires to deform
severely and to rapidly become hot. A sharp
increase in temperature could cause tread
separation, and destruction of the tires. The resulting loss of vehicle control could lead toan accident.
Wheel balance
Each wheel was correctly balanced when your ve-
hicle was new, but the wheels will become unbal-
anced as the tires become worn during use. Wheel
imbalance causes the steering wheel to vibrate
slightly at certain vehicle speeds and detracts fromthe vehicle ’s straight-line stability. It can also cause
steering and suspension system problems and ab-
normal tire wear. If you suspect that the wheels are
not correctly balanced, have them checked and ad-
justed by your SUBARU dealer. Also have them ad-
justed after tire repairs and after tire rotation. NOTE Loss of correct wheel alignment* causes the tires to wear on one side and reduces the ve-
hicle’ s running stability. Contact your SUBARU dealer if you notice abnormal tire wear.
* : The suspension system is designed to hold each wheel
at a certain alignment (relative to the other wheels and to
the road) for optimum straight-line stability and cornering
performance.
Wear indicators
A) New tread
B) Worn tread
1) Tread wear indicator
Each tire incorporates a tread wear indicator, which
becomes visible when the depth of the tread
grooves decreases to 0.063 in. (1.6 mm). A tire must

Maintenance and service
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be replaced when the tread wear indicator appears
as a solid band across the tread.
WARNING
When a tire’s tread wear indicator becomes
visible, the tire is worn beyond the acceptable
limit and must be replaced immediately. With atire in this condition, driving at high speeds inwet weather can cause the vehicle to hydro-plane. The resulting loss of vehicle control can lead to an accident.
NOTE
For safety, inspect tire tread regularly and re-
place the tires before their tread wear indicators
become visible.
Tire rotation
Tire wear varies from wheel to wheel. 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 switch-
ing the front and rear tires on the right-hand side of
the vehicle 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.)
Replace any damaged or unevenly worn tire at the
time of rotation. After tire rotation, adjust the tire
pressures and make sure the wheel nuts are cor-
rectly tightened.

Maintenance and service
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After driving approximately 600 miles (1,000 km),
check the wheel nuts again and retighten any nutthat has become loose. Tire replacement
The wheels and tires are important and integral
parts of your vehicle ’s design; they cannot be
changed arbitrarily. The tires fitted as standard
equipment are optimally matched to the characteris-
tics of the vehicle and were selected to give the best
possible combination of running performance, ride
comfort, and service life. It is essential for every tireto have a size and construction matching those
shown on the tire placard and to have a speed sym-
bol 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 incorrect body-to-tire clearances and
inappropriately changes the vehicle ’s ground clear-
ance.
All four tires must be the same in terms of manufac-
turer, brand (tread pattern), construction, and size.
You are advised to replace the tires with new ones
that are identical to those fitted as standard equip- ment.
For safe vehicle operation, SUBARU recommends
replacing all four tires at the same time. NOTE
Unidirectional tires: Some tires have a specified direction of rotation. A tire of this type has an ar-
row or other mark on its side wall to indicate thedirection of rotation. Install it so that the direc-tion of rotation is correct when the vehicle isdriven forward.