Filler Cap - Porsche 928 1979 Owner's Manual

Fuel filler cap
The fuel filler cap is located under the flap
in the rear quarter panel behind the right
rear wheel.
W h e n putting the cap back on the fuel filler
neck, be sure cap is securely seated. Twist
cap counter-clockwise, until it stops with an
audible click.
We recommend you turn off the engine when
filling the fuel tank.
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Fuel tank capacity
Fuel tank capacity is listed under "Filling
C a p a c i t i e s " .
Fuel Recommendation
Your Porsche is equipped with a catalytic
converter and must use UNLEADED FUEL
O N L Y . Minimum octane rating is 91 RON
(87 C L C rating on U.S. fuel pumps).
The use of UNLEADED
critically important to the life of the catalytic
converter. Deposits from leaded gasolines
will ruin the converter and make it ineffec-
tive as an emission control device.
Cars with a catalytic converter
smaller fuel tank opening, and gas station
pumps have smaller nozzles. This will pre-
vent accidental pumping of leaded fuel into
cars with a catalytic converter.
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.
Porsche recommends not to use any fuel
additives.
Octane ratings
Octane rating indicates a gasoline's ability
to resist detonation. Therefore, buying the
correct octane gas is important to prevent
engine damage.
Regular fuels have an octane rating ranging
f r o m 91 to 95 RON (Research Octane Num-
ber), which corresponds to 87 to 91 CLC
(U.S. Cost of Living Council octane rating).
The 91 RON octane rating which you will
find on a label on the right side
engine compartment of your car is based on
FUEL ONLY is the research method. The CLC octane rating
usually displayed on U.S. gasoline pumps is
calculated as research octane number plus
motor octane number, divided by 2, that is:
have a
The C L C octane rating is usually 4 points
lower than the RON rating:
91 RON equals
95 RON equals
Never carry additional fuel in portable con-
tainers in your car. Such containers, full or
partially empty, may leak, cause an explo-
sion, or result in fire in case of an explosion.
of the
87 C L C
91 CLC