Ford Mercury Manual Del Usuario página 791

Maintenance and Specifications
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
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.
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.
Fuel quality
If you are experiencing starting, rough idle or hesitation driveability
problems, try a different brand of unleaded gasoline. If the problems
persist, see your authorized dealer.
Do not add aftermarket fuel additive products to your fuel tank. It
should not be necessary to add any aftermarket products to your fuel
tank if you continue to use high quality fuel of the recommended octane
rating. These products have not been approved for your engine and
could cause damage to the fuel system. Repairs to correct the effects of
using an aftermarket product in your fuel may not be covered by your
warranty.
Many of the world's automakers approved the World-Wide Fuel Charter
that recommends gasoline specifications to provide improved
performance and emission control system protection for your vehicle.
Gasolines that meet the World-Wide Fuel Charter should be used when
available. Ask your fuel supplier about gasolines that meet the
World-Wide Fuel Charter.
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.
358
2010 Mountaineer (mnt)
Owners Guide (own2002), 1st Printing
USA (fus)
87
(R+M)/2 METHOD