Mercedes-Benz M-Class 2012 Owners Manual - Manual (Page 388)

Fuel consumption
Ethanol (E85) contains less energy per gallon
than gasoline. To ensure that the engine
performance with ethanol (E85) is similar to
that when using gasoline, the engine must
burn more ethanol. As a result, it is to be
expected that fuel consumption will increase
when using ethanol fuel (E85), compared to
gasoline.
Maintenance
Inform your authorized Mercedes-Benz
Center that you are operating or have
operated the vehicle with ethanol (E85).
Low outside temperatures
Starting times may significantly increase at
temperatures below 32 ‡ (0 † ). At low
outside temperatures, Mercedes-Benz
recommends the use of an auxiliary heater.
For further information, consult an authorized
Mercedes-Benz Center.
Rough idling may also be experienced at low
outside temperatures until the engine is fully
warmed up.
Ethanol (E85) is unsuitable for use if outside
temperatures fall below 14 ‡ (-10 † ).
High outside temperatures
At outside temperatures above 95 ‡ (35 † ),
the time required for the starting procedure
may increase and be accompanied by rough
idling following the start.
Fuel requirements
Gasoline engines
Use only premium-grade unleaded gasoline.
The octane number should be at least 91.
Details can be found on the gas pump. The
octane number is the average value of the
Research Octane Number (RON) and the
Motor Octane Number (MON): (RON +
MON) / 2, also known as knock resistance.
Reformulated gasoline (RFG) and/or
unleaded gasoline with additives can be used.
However, the concentration of additives in
the fuel must be less than 10%, e.g.
R Ethanol
R TAME
R ETBE
R IPA
R TBA
For MTBE, the concentration should not
exceed 15%.
The concentration of methanol in gasoline
including other additives must not exceed 3%.
Using mixtures of methanol and ethanol is not
permitted. Gasohol, a mixture of 10% ethanol
and 90% unleaded gasoline, can be used.
All of these mix fuels must fulfill the fuel
requirements, e.g.:
R knock resistance
R boiling point
R vapor pressure
Diesel engines – important safety notes
! Only use commercially available ULTRA-
LOW SULFUR DIESEL FUEL (ULSD, 15 ppm
MAXIMUM SULFUR) that meets the
ASTM D975 standard. Failure to use
ULTRA-LOW SULFUR DIESEL FUEL (ULSD)
can severely damage the vehicle's exhaust
gas aftertreatment system.
! Do not fill the tank with gasoline. Do not
blend diesel fuel with gasoline or kerosene.
Otherwise, the fuel system and the engine
could be damaged.
To prevent malfunctions, diesel fuel with
improved flow characteristics is available in
the winter months. Check with your gas
station.
Information on the fuel grade can usually be
found on the gas pump. If the information
cannot be found on the gas pump, ask the gas
station personnel. For further information,
consult an authorized Mercedes-Benz Center
386
Service products and capacities
Technical
data