FORD 2006 Fusion v.1 - Manual (Page 227)

If you do not use the proper fuel filler cap, excessive pressure or
vacuum in the fuel tank may damage the fuel system or cause
the fuel cap to disengage in a collision, which may result in possible
personal injury.
Choosing the right fuel
Use only UNLEADED 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. Studies indicate that
these additives can cause your vehicle’s emission control system to
deteriorate more rapidly. In Canada, premium grade fuel generally
contains more metallic additives than regular fuel. We recommend using
regular grade fuel. In Canada, many fuels contain metallic additives, but
fuels free of such additives may be available; check with your local fuel
dealer.
Do not use fuel containing methanol. It can damage critical fuel system
components.
Repairs to correct the effects of using a fuel for which your vehicle was
not designed may not be covered by your warranty.
Octane recommendations
Your vehicle is designed to use
“Regular” unleaded gasoline with
pump (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.
87
(R+M)/2 METHOD
2006 Fusion (fsn)
Owners Guide (post-2002-fmt)
USA (fus)
Maintenance and Specifications
227