90
Controls, Instruments If the battery voltage drops abruptly, a warning
m e s s a g e w i l l b e d i s p l a y e d b y t h e o n - b o a rd c o m p u -
ter.
If the warning is displayed by the on-board
computer while the engine is running or while
driving:
fStop the car in a safe place and stop the
engine.
Possible causes
– Defect in the battery charging system.
– Broken drive belt. Warning!
Risk of an accident and risk of engine dam-
age.
A broken drive belt means there is no power
assistance to the steering (more effort is re-
quired to steer) and coolant pump function
will stop.
fDo not continue driving.
fHave the fault remedied at the nearest author-ized Porsche dealer. The warning light in the instrument panel comes
on when the ignition is first turned on and remains
on briefly as a bulb check. If the light does not
come on, have the bulb replaced promptly.
If the warning lights in the instrument panel and on-
board computer come on and remain on while
driving, it suggests:
– a potential engine control problem and the
need for system service or
– an improperly fastened tank cap or
– refueling with engine running.
Although the vehicle is usually driveable and will
not require towing, see your dealer for service as
soon as possible.
Caution!
If the Check engine light in the instrument
panel is flashing, severe catalytic converter
damage and power loss will soon occur.
Prolonged driving with the Check engine light
on could cause damage to the emission con-
trol system. It also could affect fuel economy
and driveability.
fHave the fault remedied at the nearest author-ized Porsche dealer immediately.
Battery
Check Engine
Warning Light
188
Maintenance, Car Care
Fuel Recommendations Your Porsche is equipped with catalytic convert-
ers and must use UNLEADED FUEL ONLY.
Your engine is designed to provide optimum per-
formance and fuel economy using unleaded premi-
um fuel with an octane rating of 98 RON
(93
CLC or AKI). Porsche therefore recom-
mends 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
Octane™ knock control“ will adapt the ignition tim-
ing, if necessary.
T h e u s e o f U N L E A D E D F U E L O N LY i s c r i t i c a l l y
important to the life of the catalytic convert-
ers. Deposits from leaded fuels will ruin the
converters and make it ineffective as an
emission control device.
Cars with catalytic converters have a smaller fuel
tank opening, and gas station pumps 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 rec-
ommend you do not take your car to areas or
countries where unleaded fuel may not be availa-
ble.
Octane ratings Octane rating indicates a fuel’s ability to resist det-
onation. 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. Cost of Living Council oc-
tane rating) or AKI (antiknock index) 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 alcohol and ether Some areas of the U.S. require oxygenated fuels
during certain portions of the year. Oxygenated fu-
els are fuels which contain alcohols (such as meth-
anol or ethanol) or ether (such as MTBE).
Under normal conditions, the amount of these
compounds in the fuel will not affect driveability.
You may use oxygenated fuels in your Porsche,
provided the octane requirements for your vehicle
are met. We recommend, however, to change to a
different fuel or station if any of the following prob-
lems 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. RON MON+
2 ---------------------------------------------------- o rRM+
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