Subaru 2007 Impreza-WRX Owner's Manual page 313

Washer fluid level gauge
Remove the washer tank filler cap, then
check the fluid level indicated by the level
gauge (attached to the inside of the cap).
If the level is near the "Low" mark, add
fluid until it reaches the "Hi" level on the
level gauge or the "FULL" mark on the
tank.
Use windshield washer fluid. If windshield
washer fluid is unavailable use clean
water.
In areas where water freezes in winter,
use an anti-freeze type windshield washer
fluid. SUBARU Windshield Washer Fluid
contains 58.5% methyl alcohol and 41.5%
surfactant, by volume. Its freezing tem-
perature varies according to how much it
is diluted, as indicated in the following
table.
Washer Fluid Freezing
Concentration Temperature
30%
10.48F (−128C)
−48F (−208C)
50%
−498F (−458C)
100%
CAUTION
Never use engine coolant as washer
fluid because it could cause paint
damage.
In order to prevent freezing of washer
fluid, check the freezing temperatures in
the table above when adjusting the fluid
concentration to the outside temperature.
If you fill the reservoir tank with a fluid with
Maintenance and service
a different concentration from the one
used previously, purge the old fluid from
the piping between the reservoir tank and
washer nozzles by operating the washer
for a certain period of time. Otherwise, if
the concentration of the fluid remaining in
the piping is too low for the outside
temperature, it may freeze and block the
nozzles.
CAUTION
Adjust the washer fluid concentra-
tion appropriately for the outside
temperature. If the concentration is
inappropriate, sprayed washer fluid
may freeze on the windshield and
obstruct your view, and the fluid
may freeze in the reservoir tank.
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