Mercury 7.4L Bravo Three, Operation & Maintenance Manual

Page: 49 / 134

47
CA261
Specifications
Fuel Recommendations
IMPORTANT: Use of improper gasoline can damage your en-
gine seriously. Engine damage resulting from use of improper
gasoline is considered misuse of engine, and damage caused
thereby will not be covered under the limited warranty.
FUEL RATINGS
MerCruiser engines will operate satisfactorily when using a major
brand of unleaded gasoline as follows:
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 accept-
able. If unleaded gasoline is not available, use a major brand of
leaded gasoline.
CA291
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 is 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”
also.
These “Reformulated Gasolines” are acceptable for use in your Mer-
Cruiser engine.
CA277
GASOLINES CONTAINING ALCOHOL
If the gasoline in your area contains either “methanol” (methyl alco-
hol) or “ethanol” (ethyl alcohol), you should be aware of certain ad-
verse 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.