Gasoline Containing Alcohol; Bu16 Butanol Fuel Blends; Methanol And Ethanol Fuel Blends; Engine Oil - Mercury 3.0 MPI ECT Operation & Maintenance Manual

Gasoline Containing Alcohol

Bu16 Butanol Fuel Blends

Fuel blends of up to 16.1% butanol (Bu16) that meet the published Mercury Marine fuel rating requirements are an acceptable
substitute for unleaded gasoline. Contact your boat manufacturer for specific recommendations on your boat's fuel system
components (fuel tanks, fuel lines, and fittings).

Methanol and Ethanol Fuel Blends

IMPORTANT: The fuel system components on your Mercury Marine engine will withstand up to 10% alcohol (methanol or
ethanol) content in the gasoline. Your boat's fuel system may not be capable of withstanding the same percentage of alcohol.
Contact your boat manufacturer for specific recommendations on your boat's fuel system components (fuel tanks, fuel lines,
and fittings).
Be aware that gasoline containing methanol or ethanol may cause increased:
• Corrosion of metal parts
• Deterioration of rubber or plastic parts
• Fuel permeation through the rubber fuel lines
• Likelihood of phase separation (water and alcohol separating from the gasoline in the fuel tank)
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.
IMPORTANT: If you use gasoline that contains or might contain methanol or ethanol, you must increase the frequency of
inspection for leaks and abnormalities.
IMPORTANT: When operating a Mercury Marine engine on gasoline containing methanol or ethanol, do not store the gasoline
in the fuel tank for long periods. Cars normally consume these blended fuels before they can absorb enough moisture to cause
trouble; boats often sit idle long enough for phase separation to take place. Internal corrosion may occur during storage if
alcohol has washed protective oil films from internal components.

Engine Oil

For optimum engine performance and maximum protection, use the following oil:
Application
All MerCruiser engines
IMPORTANT: Lubrication requirements for catalyzed engines differ from the requirements for noncatalyzed engines. Some
marine‑grade lubricants contain high levels of phosphorus. Although these high‑phosphorus lubricants may allow acceptable
engine performance, exposure over time will damage the catalyst. Catalysts damaged by lubricants containing high levels of
phosphorus may not be covered by the MerCruiser Limited Warranty.
If Mercury/Quicksilver 25W‑40 Synthetic Blend Engine Oil is unavailable, use the following lubricants, listed in order of
recommendation.
1. Mercury/Quicksilver 25W‑40 Mineral NMMA FC‑W Catalyst Compatible.
IMPORTANT: If you are servicing a catalyst engine, use the following oils for short periods of time only.
2. Other recognized brands of NMMA FC‑W Catalyst Compatible rated 4‑cycle oil.
3. Other recognized brands of NMMA FC‑W rated 4‑cycle oils.
4. A good‑grade, straight‑weight detergent automotive oil according to the last row of the operating chart below.
NOTE: We do not recommend nondetergent oils, multi‑viscosity oils (other than as specified), non‑FC‑W rated synthetic oils,
low‑quality oils, or oils that contain solid additives.
90-8M0113856 DECEMBER 2015
eng
Recommended Oil
Mercury/Quicksilver 25W‑40 Synthetic Blend Engine Oil, NMMA FC‑W Catalyst Compatible rated
WARNING
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Section 3 - Specifications
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