Subaru WRX & WRX STI Manuals 2018 WRX & WRX STI Owner’s Manual | Page 356

7-4
Starting and operating/Fuel
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.
! 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 light 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
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 ethanol
(ethyl or grain alcohol) may be used in
your vehicle, but should contain no more
than 10% ethanol for the proper operation
of your SUBARU.
Do not use any gasoline that contains
more than 10% ethanol, including from
any pump labeled E15, E30, E50 or E85
(which are only some examples of fuel
containing more than 10% ethanol).
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 the
following description.
. 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 AND if 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.
. Fuel system damage or driveability
problems which result from the use of
improper fuel are not covered under the
SUBARU Limited Warranty.
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.