Fuel And Oil; Fuel Recommendations - Mercury 2.5 Operation And Installation Manual

Fuel Recommendations

IMPORTANT: Use of improper gasoline can damage your engine. Engine
damage resulting from the use of improper gasoline is considered misuse
of the engine, and damage caused thereby will not be covered under the
limited warranty.
FUEL RATINGS
Mercury Marine engines will operate satisfactorily when using a major brand of
unleaded gasoline meeting the following specifications:
USA and Canada ‑ having a posted pump octane rating of 87 (R+M)/2
minimum. Premium gasoline (92 [R+M]/2 octane) is also acceptable. Do not
use leaded gasoline.
Outside USA and Canada ‑ having a posted pump octane rating of 90 RON
minimum. Premium gasoline (98 RON) is also acceptable. If unleaded gasoline
is not available, use a major brand of leaded gasoline.
USING REFORMULATED (OXYGENATED) GASOLINES (USA ONLY)
This type of gasoline is required in certain areas of the USA. The two types of
oxygenates used in these fuels are alcohol (ethanol) or ether (MTBE or ETBE).
If ethanol is the oxygenate that is used in the gasoline in your area, refer to
Gasolines Containing Alcohol.
These reformulated gasolines are acceptable for use in your Mercury Marine
engine.
GASOLINES CONTAINING ALCOHOL
If the gasoline in your area contains either methanol (methyl alcohol) or ethanol
(ethyl alcohol), you should be aware of certain adverse effects that can occur.
These adverse effects are more severe with methanol. Increasing the
percentage of alcohol in the fuel can also worsen these adverse effects.
Some of these adverse effects are caused because the alcohol in the gasoline
can absorb moisture from the air, resulting in a separation of the water/alcohol
from the gasoline in the fuel tank.
The fuel system components on your Mercury Marine engine will withstand up
to 10% alcohol content in the gasoline. We do not know what percentage your
boat's fuel system will withstand. Contact your boat manufacturer for specific
recommendations on the boat's fuel system components (fuel tanks, fuel lines,
and fittings). Be aware that gasolines containing alcohol may cause increased:
• Corrosion of metal parts
• Deterioration of rubber or plastic parts
• Fuel permeation through rubber fuel lines
• Starting and operating difficulties
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FUEL AND OIL

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