2003 SUBARU IMPREZA WRX oil viscosity

Driving tips
8-10
it more prone to tip over. If you must rock the vehicle to free it from sand or
mud, depress the accelerator pedal slightly and
move the selector lever back and forth between “D”
and “R” repeatedly. Do not race the engine. For the
best possible traction, avoid spinning the wheels
when trying to free the vehicle.
When the road surface is extremely slippery, you
can obtain better traction by starting the vehicle withthe transmission in 2nd than 1st (both for MT and
AT). Never equip your vehicle with tires larger than
those specified in this manual. Frequent driving of an AWD vehicle under hard-
driving conditions such as rough roads or off roads
will necessitate more frequent replacement of engine
oil, brake fluid and transmission oil than that specified
in the maintenance schedule described in the “War -
ranty and Maintenance Booklet ”.
Remember that damage done to your Subaru while
operating it off-road and not using common sense
precautions such as those listed above is not eligi-ble for warranty coverage. Winter driving

Operation during cold weather
Carry some emergency equipment, such as tire
chains, a window scraper, a bag of sand, flares, a small shovel, and jumper cables.
Check the battery and cables. Cold temperatures
reduce battery capacity. The battery must be in
good condition to provide enough power for cold
winter starts.
Use an engine oil of proper grade and viscosity for

11
11-1
– CONTINUED –
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
11-10
Engine oil Checking the oil level
Check the engine oil level at each fuel stop.
1. Park the vehicle on a level surface and stop theengine.
2. Pull out the dipstick, wipe it clean, and insert it again.
3. Be sure the dipstick is correctly inserted until it
stops with the graphic symbol i on its top ap-
pearing as shown in the illustration.
1) Notch
2) Upper level 3) Lower level
4) Front of vehicle
4. Pull out the dipstick again and check the oil level on it. If it is below the lower level, add oil to bring thelevel up to the upper level.
CAUTION
Use only engine oil with the recommended
grade and viscosity. Be careful not to spill engine oil when ad-
ding it. If oil touches the exhaust pipe, it may
cause a bad smell, smoke, and/or a fire.

Maintenance and service
11-13
– CONTINUED –
Recommended grade and viscosity
Oil grade: API classification SL or SJ with the words “ENERGY CONSERVING ” (if you cannot obtain
the oil with the SL or SJ grade, you may use SH or SG grade oil.) or the new API certification mark
(Starburst mark) displayed on the container.
API Service label
1) Indicates the oil quality by API designations
2) Indicates the SAE oil viscosity grade
3) Indicates that the oil has fuel saving capabilities

Maintenance and service
11-14
New API Certification Mark (Starburst Mark)
In choosing an oil, you want the proper quality and
viscosity, as well as one that will add to fuel econo-
my. The following table lists the recommended vis-
cosities and applicable temperatures.
When adding oil, different brands may be used to-
gether as long as they are the same API classifica-
tion and SAE viscosity as those recommended bySUBARU.SAE viscosity number and applicable temperature
*) 5W-30 is preferred.
Engine oil viscosity (thickness) affects fuel economy.
Oils of lower viscosity provide better fuel economy.
However, in hot weather, oil of higher viscosity is re-
quired to properly lubricate the engine.
CAUTION
Use only engine oil with the recommended
grade and viscosity.

Maintenance and service
11-15
– CONTINUED –
Recommended grade and viscosity under severe driving conditions
If the vehicle is used in desert areas, in areas with
very high temperatures, or used for heavy-duty ap-
plications such as towing a trailer, use of oil with the
following grade and viscosities is recommended.
API classification SL or SJ: SAE viscosity No.: 30, 40, 10W-50, 20W-40,
20W-50
Synthetic oil
You can use synthetic engine oil that meets the
same requirements given for conventional engine
oil. When using synthetic oil, you must use oil of the
same classification, viscosity and grade shown inthis owner ’s manual, and must follow the oil and filter
changing intervals shown in the maintenance schedule. Cooling system
WARNING
Never attempt to remove the radiator cap until the engine has been shut off and has cooled
down completely. Since the coolant is underpressure, you may suffer serious burns from a
spray of boiling hot coolant when the cap isremoved.
CAUTION

The cooling system has been filled at the
factory with a high quality, corrosion-inhibit-
ing, year-around coolant which provides protection against freezing down to –33°F
(–36 °C). For adding, use genuine SUBARU
coolant or an equivalent: a mixture of 50%
soft water and 50% ethylene-glycol basis cool-
ant. Use of improper coolants may result in
corrosion in the cooling system. It is impor- tant to maintain protection against freezing and corrosion, even if freezing temperaturesare not expected. Never mix different kinds ofcoolant.

Maintenance and service
11-26
Turbo model
Check the oil level monthly.
1. Park the vehicle on a level surface and stop theengine.
2. Pull out the dipstick, wipe it clean, and insert itagain.1) Upper level 2) Lower level
3. Pull out the dipstick again and check the oil level
on it. If it is below the lower level, add oil through thedipstick hole to bring the level up to the upper level. Recommended grade and viscosity
Each oil manufacturer has its own base oils and ad-
ditives. Never use different brands together.
Oil grade: API classification GL-5

Maintenance and service
11-30
1) Upper level 2) Lower level
3. Pull out the dipstick again and check the oil level on it. If it is below the lower level, add oil to bring thelevel up to the upper level. Recommended grade and viscosity
Each oil manufacturer has its own base oils and ad-
ditives. Never use different brands together.
Oil grade: API classification GL-5SAE viscosity No. and Applicable Temperature