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Maintenance and Car Care
Fuel Recommendations
Your Porsche is equipped with catalytic
converters and must use
UNLEADED FUEL
ONLY
.
Your engine is designed to provide optimum
performance and fuel economy using unleaded
premium fuel with an octane rating of
98 RON
(93 CLC or AKI)
. Porsche therefore
recommends the use of these fuels in your
vehicle.
Porsche also recognizes that these fuels may not
always be available. Be assured that your vehicle
will operate properly on unleaded premium fuels
with octane numbers of at least
95 RON
(90 CLC or AKI)
, since the engine’s “Electronic
Oktane™ knock control” will adapt the ignition
timing, if necessary.
It is important to observe the regular service
intervals, and particularly the oil change intervals,
specified in the “Maintenance” booklet.
The use of UNLEADED FUEL ONLY is critically
important to the life of the catalytic
converters. Deposits from leaded fuels will
ruin the converters and make them
ineffective as an emission control device.
Cars with catalytic converters have a smaller fuel
tank opening, and gas station pumps that
dispense unleaded fuel have smaller nozzles. This
will prevent accidental pumping of leaded fuel into
cars with catalytic converters.
Unleaded fuels may not be available outside the
continental U.S. and Canada. Therefore, we
recommend you do not take your car to areas or
countries where unleaded fuel may not be
available.
Octane ratings
Octane rating indicates a fuel’s ability to resist
detonation. Therefore, buying the correct octane
gas is important to prevent engine “damage”.
The RON octane rating is based on the research
method. The CLC (U.S.
C
ost of
L
iving
C
ouncil
octane rating) or AKI (
a
nti
k
nock
i
ndex) octane
rating usually displayed on U.S. fuel pumps is
calculated as research octane number plus motor
octane number, divided by 2, that is written as:
The CLC or AKI octane rating is usually lower than
the RON rating:
For example: 95 RON equals 90 CLC or AKI.
Fuels containing ethanol
Do not use any fuels containing more than
10 percent ethanol by volume.
We recommend, however, to change to a different
fuel or station if any of the following problems
occur with your vehicle:
– Deterioration of driveability and performance.
– Substantially reduced fuel economy.
– Vapor lock and non-start problems, especially
at high altitude or at high temperature.
– Engine malfunction or stalling.
Fuel Evaporation Control
Fuel tank venting
The evaporation chamber and the carbon canister
prevent fuel vapors from escaping to the
atmosphere at extreme high outside
temperatures, when driving abruptly around
curves and when the car is parked at an incline or
in any other nonlevel position.
Vapor control system and storage
When the fuel tank is filled, vapors are collected in
the evaporation chamber by a vent line leading the
vapors to the carbon canister where they are
stored as long as the engine does not run.
Purge system
When the engine is running, the fuel vapors from
the canister will be mixed with fresh air from the
ambient air of the canister. This mixture will be
directed to the intake air housing by the tank vent
line, mixed with the intake air and burned during
normal combustion.
RON+MON
2
R+M
2
or