octane JAGUAR XJ 2004 X350 / 3.G Owners Manual

4-66 On the Road
Fuel filler flap manual release
If the fuel filler flap fails to release it can
be manually unlocked as follows:
1. In the luggage compartment, remove
the carpet from the right-hand side,
behind the rear light. To do this, turn
the carpet securing screws a ¼ turn
and then firmly pull the top corner of
the carpet down.
2. Locate the fuel flap release mechanism and pull the knob rearwards. This will
release the flap to gain access to the
filler cap and enable the vehicle to be
refuelled.
3. Report the fault to a Jaguar Retailer. Unleaded fuel
All vehicles are fitted with a catalytic
system and can only use unleaded fuel.
Unleaded fuel must be used for the
emission control system to operate
properly. Its use will also reduce spark
plug fouling, exhaust system corrosion
and engine oil deterioration.
The preferred fuel should have an octane
rating of at least 95 RON (Research
Octane Number).
‘Super Green’ Plus 98 RON unleaded fuel
(where available) may be used as an
alternative to the standard 95 RON
unleaded fuel. Some countries have only 91 RON fuel
available. The vehicles in these countries
are specially calibrated to use this fuel.
Using unleaded fuel with an octane rating
lower than recomm
ended can cause
persistent, heavy ‘spark knock’ (a metallic
rapping noise). If severe, this can lead to
engine damage.
If a heavy ‘spark knock’ is detected even
when using fuel of the recommended
octane rating, or if you hear steady ‘spark
knock’ while holding a steady speed on
level roads consult a Jaguar Retailer to
have the problem corrected. Failure to do
so is misuse of the vehicle, for which
Jaguar Cars Limited, is not responsible.
However, occasional light ‘spark knock’
for a short time while accelerating or
driving up hill, may occur.
Emission control components
Owing to the legislative requirements or
options available in some countries,
a Jaguar Retailer should be consulted
where any doubt exists as to the precise
emission control system specification of
this vehicle.

On the Road 4 - 67
Fuels containing alcohol
Caution: Take care not to spill fuel
during refuelling. Fuel containing
alcohol can cause paint damage,
which may not be covered under the
warranty.
Some fuel suppliers sell fuel containing
alcohol without advertising its presence.
Where uncertainty exists check with the
service station operator.
Note: Some difficulty in starting may be
encountered when using alcohol blended
fuel.
Ethanol
Fuels containing up to 10 per cent
ethanol (grain alcohol) may be used.
Ensure the fuel has octane ratings no
lower than those recommended for
unleaded fuel. Most drivers will not
notice any operating difference with fuel
containing ethanol. If a difference is
detected, the use of conventional
unleaded fuel should be resumed. Methanol
Some fuels contain methanol (methyl or
wood alcohol). If you use fuels containing
methanol the fuels must also contain
co-solvents and corrosion inhibitors for
methanol. Also, do not use fuels that
contain more than three per cent
methanol even if they
contain co-solvents
and corrosion inhibitors. Fuel system
damage or vehicle performance problems
resulting from the use of such fuels is not
the responsibility of Jaguar Cars Limited,
and may not be covered under the
warranty.
Methyl Tertiary Butyl Ether (MTBE)
Unleaded fuel containing an oxygenate
known as MTBE can be used provided the
ratio of MTBE to conventional fuel does
not exceed 15 per cent.
MTBE is an ether based compound,
derived from petroleum, which has been
specified by several refiners as the
substance to enhance the octane rating of
fuel.