Subaru 2013 Impreza Owner's Manual page 29

Remove the washer tank filler cap, then
add windshield washer fluid until it
reaches the "FULL" mark on the tank. 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%
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
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.
Maintenance and service
CAUTION
. Adjust the washer fluid concen-
tration appropriately for the out-
side temperature. If the concen-
tration is inappropriate, sprayed
washer fluid may freeze on the
windshield and obstruct your
view, and the fluid may freeze in
the reservoir tank.
. State or local regulations on
volatile organic compounds may
restrict the use of methanol, a
common windshield washer anti-
freeze additive. Washer fluids
containing non-methanol anti-
freeze agents should be used
only if they provide cold weather
protection without damaging
your vehicle's paint, wiper blades
or washer system.
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