open gas tank PORSCHE BOXSTER 2005 2.G Owners Manual

180
Maintenance, Car Care
Fuel Recommendations Your Porsche is equipped with catalytic conver-
ters 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
Oktane™ knock control“ will adapt the ignition ti-
ming, 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 conver-
ters. 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 re-
commend you do not take your car to areas or
countries where unleaded fuel may not be availab-
le.
Octane ratings Octane rating indicates a fuel’s ability to resist de-
tonation. 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 me-
thanol 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 pro-
blems 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+
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