FORD 2008 E-450 v.2 - Manual (Page 252)

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. Your vehicle was not designed to run on E85 fuels that are
blended with a maximum of 85% ethanol. Do not use fuel containing
methanol. It can damage critical fuel system components.
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. Studies indicate that
these additives can cause your vehicle’s emission control system to
deteriorate more rapidly.
Repairs to correct the effects of using a fuel for which your vehicle was
not designed may not be covered by your 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
Do not be concerned if your engine
sometimes knocks lightly. However,
if it knocks heavily under most
driving conditions while you are
using fuel with the recommended
octane rating, see your authorized dealer to prevent any engine damage.
Unleaded Gasoline Engines
Your vehicle is designed to use “Regular” unleaded gasoline with an
(R+M)/2 octane rating of 87. We do not recommend the use of gasolines
labeled as “Regular” that are sold with octane ratings of 86 or lower in
high altitude areas.
FFV engine (if equipped)
Your vehicle is designed to use Fuel Ethanol (Ed75–Ed85),“Regular”
unleaded gasoline or any mixture of the two fuels.
U.S. government regulations require fuel ethanol dispensing
pumps to have a small, square, orange and black label with the
common abbreviation or the appropriate percentage for that
region. Use of other fuels such as Fuel Methanol may cause
powertrain damage, a loss of vehicle performance, and your
warranty may be invalidated.
87
(R+M)/2 METHOD
2008 Econoline (eco)
Owners Guide (post-2002-fmt)
USA (fus)
Maintenance and Specifications
252