Porsche Cayman Owner's Manual page 219

If there is a defect in the automatic unlocking
system:
Open the passenger door.
Pull the ring in the right-hand door aperture
(arrow).
Refueling
Fuel tank capacity
The fuel filling capacity is approx. 16.9 U.S.gal-
lons/64 liters.
Porsche does not recommend the use of fuel
additives.
Fuel is highly ammable and harmful to
health.
Please observe the chapter "CAPACITIES" on
page 301.
Procedure
1. Important: Stop the engine and switch off the
ignition.
2. Slowly unscrew the tank cap . Hang the tank
cap on the plastic strap of the filler flap.
3. Insert fuel-hose nozzle fully into the filler neck
with the handle of the fuel-hose nozzle facing
down.
4. Do not add further fuel once the correctly
operated automatic fuel-hose nozzle has
switched off. Fuel could spray or could run
over in warm temperatures.
5. Replace the tank cap immediately after
refueling and turn it until you hear it and feel
it engage.
If you lose the tank cap, you must replace
it only with an original part to reduce the
possibility of a re in the event of a collision.
Note
The oil level is automatically measured during
refuelling.
Please observe the chapter "OIL DISPLAY AND
MEASUREMENT OF THE ENGINE OIL LEVEL"
on page 131.
Maintenance, Car Care
217