fuel pump MERCEDES-BENZ S550 2007 W221 Owner's Manual

490 OperationAt the gas station
Take off fuel filler cap and set it in di-
rection of arrow 2 in the recess on the
inside of fuel filler flap 4.
To prevent fuel vapors from escaping
into open air, fully insert filler nozzle
unit.

Only fill your tank until the filler nozzle
unit cuts out – do not top up or over-
fill.

Replace fuel cap by turning it clockwise
until it audibly engages.

Close the fuel filler flap.
Check regularly and before a long tripExample illustration from S 5501Coolant level
2Brake fluid
3Windshield washer and headlamp
cleaning system
Warning!
G
Overfilling of the fuel tank may create pres-
sure in the system which could cause a gas
discharge. This could cause the gas to spray
back out when removing the fuel pump noz-
zle, which could cause personal injury.
i
Only use premium unleaded gasoline with a
minimum Posted Octane Rating of 91 (average of
96 RON/86 MON).
Information on gasoline quality can normally be
found on the fuel pump.
More information on gasoline can be found in the
Factory Approved Service Products pamphlet.
i
Leaving the engine running and the fuel cap
open can cause the yellow engine malfunction
indicator lamp ± to illuminate.
For more information, see the “Practical hints”
section (
page 547).
i
Opening the hood (
page 492).


664 Technical dataFuels, coolants, lubricants, etc.Premium unleaded gasoline
Fuel requirements
Use only premium unleaded fuel:

The octane number (posted at the
pump) must be 91 min. It is an average
of both the Research (R) octane num-
ber and the Motor (M) octane number:
(R+M)/2). This is also known as the
ANTI-KNOCK INDEX.
Unleaded gasoline containing oxygenates
such as ethanol, IPA, IBA and TBA can be
used provided the ratio of any one of these
oxygenates to gasoline does not exceed
10%; MTBE must not exceed 15%.
The ratio of methanol to gasoline must not
exceed 3% plus additional co-solvents.
Using mixtures of ethanol and methanol is
not allowed. Gasohol, which contains
10% ethanol and 90% unleaded gasoline,
can be used.
These blends must also meet all other fuel
requirements, such as resistance to spark
knock, boiling range, vapor pressure, etc.
Warning!
G
Gasoline is highly flammable and poisonous.
It burns violently and can cause serious
injury. Whenever you are around gasoline,
avoid inhaling fumes and skin contact, extin-
guish all smoking materials. Never allow
sparks, flame or smoking materials near
gasoline!
Switch off the engine before refueling.Warning!
G
Do not allow fuel to come into contact with
skin or clothing.
Direct skin contact with fuels and the inha-
lation of fuel vapors are damaging to health.
!
To maintain the engine’s durability and per-
formance, premium unleaded gasoline must be
used. If premium unleaded gasoline is not avail-
able and low octane fuel is used, follow these
precautions:


Have the fuel tank only partially filled with
unleaded regular and fill up with premium
unleaded as soon as possible.


Avoid full throttle driving and abrupt acceler-
ation.


Do not exceed an engine speed of 3000 rpm
if the vehicle is loaded with a light load such
as two persons and no luggage.


Do not exceed
2/3 of maximum accelerator
pedal position if the vehicle is fully loaded or
operating in mountainous terrain.