Choosing The Right Fuel; Octane Recommendations - Lincoln MKZ Hybrid Owner's Manual

Maintenance and Specifications
fill inlet lamp or CHECK FUEL FILL INLET message may not reset
immediately. It may take several driving cycles for the check fuel fill inlet
lamp or CHECK FUEL FILL INLET message to turn off. A driving cycle
consists of an engine start-up (after four or more hours with the engine
off) followed by city/highway driving. Continuing to drive with the check
fuel fill inlet lamp or CHECK FUEL FILL INLET message on may cause
the service engine soon lamp to turn on as well.
WARNING: The fuel system may be under pressure. If you hear
a hissing sound near the fuel filler door (Easy Fuel "no cap"
fuel system), do not refuel until the sound stops. Otherwise, fuel may
spray out, which could cause serious personal injury.

Choosing the right fuel

Use only 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.

Octane recommendations

"Regular" unleaded gasoline with a
pump (R+M)/2 octane rating of 87 is
recommended. 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.
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.
304
2012 MKZ Hybrid (hkz)
Owners Guide, 1st Printing
USA (fus)
87
(R+M)/2 METHOD