Fuel Quality; Choosing The Right Fuel; Diesel Engine - Ford Super Duty Owner's Manual

Fuel and Refueling 191
Pure ethanol is the alcohol which is the intoxicating agent in liquor, beer
and wine. It is distilled from the fermentation of plants such as field
corn and sugar cane. When ethanol is produced for use in motor fuels,
a small amount of gasoline is added to make it unfit for beverage use.
The resulting ethanol blend is called denatured fuel ethanol meaning that it
is denatured with 2% to 5% gasoline and is suitable for automotive use.
During the summer season, fuel ethanol may contain a maximum of 85%
denatured ethanol (Ed85) and 15% unleaded gasoline. The fuel ethanol
has a higher octane rating than unleaded regular or premium gasoline
and this allows the design of engines with greater efficiency and power.
Winter blends may contain up to 75% denatured ethanol (Ed75) and up
to 25% unleaded gasoline to enhance cold engine starts. Severely cold
weather may require additional measures for reliable starting. Refer to
the Starting chapter
Ethanol is more chemically active than gasoline. It corrodes some metals
and causes some plastic and rubber components to swell, break down or
become brittle and crack, especially when mixed with gasoline. Special
materials and procedures have been developed for flexible fuel vehicles
and the dispensers used by ethanol fuel providers.

FUEL QUALITY

Note: Use of any fuel other than those recommended may cause
powertrain damage and a loss of vehicle performance; repairs may not be
covered under warranty.

Choosing the Right Fuel

Use only UNLEADED fuel or UNLEADED fuel blended with a maximum
of 15% ethanol. Do not use fuel ethanol (E85), diesel fuel, fuel-methanol,
leaded fuel or any other fuel because it could damage or impair the
emission control system.
Your vehicle was not designed to use fuel or fuel additives with metallic
compounds, including manganese-based additives. The use of leaded fuel
is prohibited by law.
Diesel engine (if equipped)
Refer to the diesel supplement for information regarding diesel fuel
recommendations and requirements of your diesel-powered truck.
2013 F-250/350/450/550 (f23)
Owners Guide gf, 2nd Printing, December 2012
USA (fus)