Mercedes-Benz 2007 R 320 CDI Automobile User Manual


 
542
Technical data
Fuels, coolants, lubricants, etc.
Gasoline additives (gasoline engine)
A major concern among engine manufac-
turers is carbon build-up caused by gaso-
line. Mercedes-Benz recommends only the
use of quality gasoline containing additives
that prevent the build-up of carbon depos-
its.
After an extended period of using fuels
without such additives carbon deposits
can build up, especially on the intake
valves and in the combustion area, leading
to engine performance problems such as:
ț Warm-up hesitation
ț Unstable idle
ț Knocking/pinging
ț Misfire
ț Power loss
In areas where carbon deposits may be
encountered due to lack of availability of
gasolines which contain these additives,
Mercedes-Benz recommends the use of
additives approved by us for use on
Mercedes-Benz vehicles. Refer to Factory
Approved Service Products pamphlet for a
listing of approved product(s). Follow
directions on product label.
Do not blend other specific fuel additives
with fuel. This only results in unnecessary
costs and may be harmful to the engine
operation.
Damage or malfunction resulting from
poor fuel quality or from blending addition-
al fuel additives other than those tested
and approved by us for use on
Mercedes-Benz vehicles listed in the Fac-
tory Approved Service Products pamphlet
are not covered by the Mercedes-Benz
Limited Warranty.
Fuel requirements
Gasoline engine
Only use premium unleaded fuel.
ț 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 cosolvents.
Using mixtures of ethanol and methanol is
not allowed. Gasohol, which contains
10% ethanol and 90% unleaded gasoline,
can be used.