FORD 2010 E-450 v.2 - Manual (Page 289)

FFV (Flex Fuel Vehicle) fuel cap
If your vehicle is FFV capable, it will have a yellow colored fuel cap.
Choosing the right fuel
If your vehicle is a flexible fuel vehicle (FFV), use only UNLEADED
FUEL and FUEL ETHANOL (Ed75–Ed85).
If your vehicle is not a flexible fuel vehicle (FFV), then only use
UNLEADED fuel or UNLEADED fuel blended with a maximum of 10%
ethanol. Do not use fuel ethanol (E85), diesel, methanol, leaded fuel or
any other fuel.
The use of leaded fuel is prohibited by law and could damage your
vehicle.
Your vehicle was not designed to use fuel or fuel additives with metallic
compounds, including manganese-based additives.
Note: Use of any fuel other than those recommended may cause
powertrain damage, a loss of vehicle performance, and repairs may not
be covered under warranty.
Cleaner air
Ford endorses the use of reformulated “cleaner-burning” gasolines to
improve air quality, per the recommendations in the Choosing the right
fuel section.
Octane recommendations
Your vehicle is designed to use “Regular” unleaded gasoline with a pump
(R+M)/2 octane rating of 87. Some stations offer fuels posted as
“Regular” with an octane rating below 87, particularly in high altitude
areas. Fuels with octane levels below 87 are not recommended.
Maintenance and Specifications
289
2010 Econoline (eco)
Owners Guide, 2nd Printing
USA (fus)