Opel Astra 2004 Manuel D'utilisation page 32

Fuel Consumption,
Fuel, Refuelling
Fuel selector switch
Pushbutton switch Y in the central console
with control indicator showing switch
position. The pushbutton switch is used to
change over from natural gas to petrol
mode.
Natural gas
mode = Control indicator off.
Petrol mode = Control indicator on.
As soon as the natural gas tanks are empty
the system changes over automatically to
petrol mode. This is indicated by the
control indicator flashing constantly. As
soon as the natural gas tanks have been
filled again, the system changes over
automatically to natural gas mode. The
control indicator goes off.
30
Pressing the pushbutton Y when the control
indicator is flashing changes the system
over to petrol mode permanently. The
control indicator is constantly illuminated.
If the selector switch is pressed several
times within a short time, a change-over
lock is activated. The engine remains in
the operating mode in which it was last
used. The lock can only be cancelled by
a manual ignition cycle (ignition off,
ignition on).
When in petrol mode a slight loss of power
and torque is to be expected, (therefore
you need to adjust your style of driving
accordingly (e.g. when overtaking) and
vehicle loads (e.g. from trailer loads).
Every 1500 to 2000 km or every 3 months
– whichever occurs first – run the petrol
tank down to the reserve level and refuel.
This is necessary to maintain the petrol
quality required for operation.
Note:
Refuelling and operation only with petrol
with an octane number greater than or
equal to 95 RON (Premium, Premium Plus).
If you accidentally refuel with petrol with
an octane below 95 RON (Regular), avoid
driving at full load (e.g. sharp acceleration,
driving with your foot hard down on the
accelerator) whilst you run the tank down
to the reserve and then refuel with the
correct fuel.