Section 4 - Specifications 
Page  40 90-899883179   OCTOBER  2007
Fuel Requirements
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  MerCruiser  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 2 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.
These Reformulated Gasolines are acceptable for use in your Mercury MerCruiser 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 MerCruiser 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 increase:
• Corrosion of metal parts
• Deterioration of rubber or plastic parts
• Fuel permeation through rubber fuel lines
• Difficulty starting and operating the engine
!
 WARNING
Fuel  leakage  is  a  fire  or  explosion  hazard,  which  can  cause  serious  injury  or  death.
Periodically inspect all fuel system components for leaks, softening, hardening, swelling,
or  corrosion,  particularly  after  storage.  Any  sign  of  leakage  or  deterioration  requires
replacement before further engine operation.
Because  of  possible  adverse  effects  of  alcohol  in  gasoline,  we  recommend  only
alcohol‑free gasoline when possible. If the only fuel available contains alcohol or if you do
not  know  whether  the  fuel  contains  alcohol,  inspect  for  leaks  and  abnormalities  more
frequently.