Fuel Requirements - Mercedes-Benz SL 320 Operator's Manual

Fuel Requirements

Use only Premium unleaded
meeting ASTM standard D 439:
The octane number (posted at the
pump) must be 91min. It is an
average of both, the Research (R)
octane number and the Motor (M)
octane number: [(R + M)/2]. This
is also known as ANTI-KNOCK
INDEX.
Unleaded gasoline containing
oxygenates such as Ethanol, I PA,
IBA and TBA can be used provided
the ratio of any one of these
oxygenates to gasoline does not
exceed 10%, MTBE not to exceed 15%.
The ratio of Methanol to gasoline
must not exceed 3% plus additional
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..
Gasoline Additives
A major concern among engine
manufacturers is carbon build up
caused by gasoline. Mercedes- Benz
recommends to use only quality gasoline
containing additives that prevent the
build up of carbon deposits.
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:
• warm-up hesitation,
• unstable idle,
• knocking/pinging,
• misfire
• power loss.
Do not blend other specific fuel
additives with fuel. They only result in
unnecessary cost, and may be harmful to
the engine operation. Damage or
malfunctions resulting from poor fuel
quality or from blending specific fuel
additives are not covered by the
Mercedes-Benz Limited Warranty.
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