Section 4 - Specifications
Page 76
90-8M0053363
eng
NOVEMBER 2010
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.
IMPORTANT: When operating a Mercury MerCruiser engine on gasoline containing alcohol, do not store the gasoline in the fuel
tank for long periods. Whereas cars normally consume alcohol‑blend fuels before they can absorb enough moisture to cause
trouble, boats often sit idle long enough for phase separation to take place. In addition, internal corrosion may take place during
storage if alcohol has washed protective oil films from internal components.
Engine Oil
To help obtain optimum engine performance and to provide maximum protection, we strongly recommend the use of the following
oils listed in the order of recommendation:
1. MerCruiser / Quicksilver Synthetic Blend, NMMA FC‑W rated, 4 cycle oil.
2. MerCruiser / Quicksilver 25W40 NMMA FC‑W rated oil.
3. A NMMA FC‑W rated oil.
4. MerCruiser / Quicksilver 4‑cycle 25W40, non FC‑W rated oil.
5. A good grade straight weight detergent automotive oil per the operating chart below.
