Specifications

FUEL AND OIL
eng 43
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.
Mercury Marine engines will operate satisfactorily when using a
major brand of unleaded gasoline meeting the following
specifications:
MODELS 250 PRO, 300 PRO, AND 300
USA and Canada ‑ Having a posted pump Octane Rating of 92
(R+M)/2 Octane is required for best performance. Having a
posted pump Octane Rating of 87 (R+M)/2 minimum is
acceptable, however, performance losses may occur. Do not use
leaded gasoline.
Outside USA and Canada ‑ Having a posted pump Octane
Rating of 96 RON is required for best performance. Having a
posted pump Octane Rating of 90 RON minimum is acceptable,
however, performance losses may occur. If unleaded gasoline is
not available, use a major brand of leaded gasoline.
MODELS 225 AND 250
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.