2008 SUBARU LEGACY octane

Fuel
CAUTION
Use of a fuel which is low in quality
or use of an inappropriate fuel
additive may cause engine damage.
& Fuel requirements
! 2.5-liter non-turbo models
The 2.5-liter non-turbo engine is designed
to operate using unleaded gasoline with
an octane rating of 87 AKI or higher. ! 2.5-liter turbo models
The 2.5-liter turbo engine is designed to
operate using premium unleaded gasoline
with an octane rating of 91 AKI or higher. If
premium unleaded gasoline is not avail-
able, regular unleaded gasoline with an
octane rating of 87 AKI or higher may be
temporarily used. For optimum engine
performance and driveability, it is required
that you use premium grade unleadedgasoline. NOTE
Be sure to use premium unleaded
gasoline of 91 AKI or higher for a 2.5-
liter turbo engine model. If other gaso-
line (lower than 91 AKI) is used, knock-
ing, reduced output and poor accelera-
tor response will result. !
3.0-liter models
The 3.0-liter engine is designed to operate
using unleaded gasoline with an octane
rating of 91 AKI or higher. Regular
unleaded gasoline with an octane rating
of 87 AKI or higher may be used. However
for optimum engine performance and
driveability, it is recommended that you
use 91 AKI or higher grade unleaded
gasoline. You may experience reduced
output, poor accelerator response, and
reduced fuel economy when using gaso-
line with an octane rating lower than 91
AKI, depending on your driving habits and
conditions. If you experience any of these
conditions while using a lower octane
rated fuel, you may want to return to using
91 AKI octane rated fuel as soon as
possible. Additionally, if your vehicle
knocks heavily or persistently, or if you
are driving with heavy loads such as when
towing a trailer, the use of 91 AKI or higher
grade unleaded gasoline is required. !
Fuel octane rating
This octane rating is the average of the
Research Octane and Motor Octane
numbers and is commonly referred to as
the Anti Knock Index (AKI).
Using a gasoline with a lower octane
rating can cause persistent and heavy
knocking, which can damage the engine.
Do not be concerned if your vehicle
sometimes knocks lightly when you drive
up a hill or when you accelerate. See your
dealer or a qualified service technician if
you use a fuel with the specified octane
rating and your vehicle knocks heavily or
persistently. ! Unleaded gasoline
The neck of the fuel filler pipe is designed
to accept only an unleaded gasoline filler
nozzle. Under no circumstances should
leaded gasoline be used because it will
damage the emission control system and
may impair driveability and fuel economy. ! California fuel
If your vehicle was certified to California
Emission Standards as indicated on the
underhood tune-up label, it is designed to
optimize engine and emission control
system performance with gasoline that
meets the clean burning low-sulfur Cali-
fornia gasoline specifications. If you live in
any other state than California, your Starting and operating
7-3
– CONTINUED –

7-4Starting and operating
vehicle will operate on gasoline meeting
Federal specifications. Gasoline sold out-
side California is permitted to have higher
sulfur levels, which may affect the perfor-
mance of your vehicle ’s catalytic converter
and may produce a sulfur exhaust odor or
smell. SUBARU recommends that you try
a different brand of unleaded gasoline
having lower sulfur to determine if the
problem is fuel related before returning
your vehicle to an authorized dealer for
service. The CHECK ENGINE warning
light/malfunction indicator lamp may also
turn on. If this occurs, return to your
authorized SUBARU dealer for diagnosis.
If it is determined that the condition is
caused by the type of fuel used, repairs
may not be covered by your warranty. ! MMT
Some gasoline contains an octane-en-
hancing additive called MMT (Methylcy-
clopentadienyl Manganese Tricarbonyl). If
you use such fuels, your emission control
system performance may deteriorate and
the CHECK ENGINE warning light/mal-
function indicator lamp may turn on. If this
happens, return to your authorized
SUBARU Dealer for service. If it is
determined that the condition is caused
by the type of fuel used, repairs may not
be covered by your warranty. !
Gasoline for cleaner air
CAUTION
Do not let fuel spill on the exterior
surfaces of the vehicle. Fuels con-
taining alcohol may cause paint
damage, which is not covered under
the SUBARU Limited Warranty.
Your use of gasoline with detergent
additives will help prevent deposits from
forming in your engine and fuel system.
This helps keep your engine in tune and
your emission control system working
properly, and is a way of doing your part
for cleaner air. If you continuously use a
high quality fuel with the proper detergent
and other additives, you should never
need to add any fuel system cleaning
agents to your fuel tank.
Many gasolines are now blended with
materials called oxygenates. Use of these
fuels can also help keep the air cleaner.
Oxygenated blend fuels, such as MTBE
(Methyl Tertiary Butyl ether) or ethanol
(ethyl or grain alcohol) may be used in
your vehicle, but should contain no more
than 15% MTBE or 10% ethanol for the
proper operation of your SUBARU.
In addition, some gasoline suppliers are now producing reformulated gasolines,
which are designed to reduce vehicle
emissions. SUBARU approves the use of
reformulated gasoline.
If you are not sure what the fuel contains,
you should ask your service station
operators if their gasolines contain deter-
gents and oxygenates and if they have
been reformulated to reduce vehicle emis-sions.
As additional guidance, only use fuels
suited for your vehicle as explained in thefollowing. .
Fuel should be unleaded and have an
octane rating no lower than that specified
in this manual. . Methanol (methyl or wood alcohol) is
sometimes mixed with unleaded gasoline.
Methanol can be used in your vehicle
ONLY if it does not exceed 5% of the fuel
mixture ANDif it is accompanied by
sufficient quantities of the proper cosol-
vents and corrosion inhibitors required to
prevent damage to the fuel system. Do not
use fuel containing methanol EXCEPT
under these conditions. . If undesirable driveability problems are
experienced and you suspect they may be
fuel related, try a different brand of gaso-
line before seeking service at your
SUBARU dealer.

GAS STATION REFERENCE
& Fuel:
! 2.5-liter non-turbo models
Use only unleaded gasoline with an octane rating of 87 AKI or
higher. ! 2.5-liter turbo models
Use premium unleaded gasoline with an octane rating of 91 AKI
or higher. For temporary purposes if premium unleaded
gasoline is not available, you may use regular unleaded
gasoline with an octane rating of 87 AKI or higher. For optimum
engine performance and driveability, it is required that you use
premium grade unleaded gasoline. ! 3.0-liter models
Use unleaded gasoline with an octane rating of 91 AKI or
higher. Regular unleaded gasoline with an octane rating of 87
AKI or higher may be used. However for optimum engine
performance and driveability, it is recommended that you use
91 AKI or higher grade unleaded gasoline. You may experience
reduced output, poor accelerator response, and reduced fuel
economy when using gasoline with an octane rating lower than
91 AKI, depending on your driving habits and conditions. If you
experience any of these conditions while using a lower octane
rated fuel, you may want to return to using 91 AKI octane rated
fuel as soon as possible. Additionally, if your vehicle knocks
heavily or persistently, or if you are driving with heavy loads
such as when towing a trailer, the use of 91 AKI or higher grade
unleaded gasoline is required. &
Fuel octane rating
This octane rating is the average of the Research Octane and
Motor Octane numbers and is commonly referred to as the Anti
Knock Index (AKI). Refer to “Fuel ”section in this manual.
& Fuel capacity:
16.9 US gal (64 liters, 14.1 Imp gal) & Engine oil:
Use only API classification SM with the words “ENERGY
CONSERVING ”or ILSAC GF-4, which can be identified with
the ILSAC certification mark (Starburst mark).& Engine oil capacity:
2.5-liter models: 4.2 US qt (4.0 liters, 3.5 Imp qt)
3.0-liter models: 5.8 US qt (5.5 liters, 4.8 Imp qt)