Ford Town Car 2006 Owner's Manual page 246

Maintenance and Specifications
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
87
sometimes knocks lightly. However,
if it knocks heavily under most
driving conditions while you are
(R+M)/2 METHOD
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 a pump
(R+M)/2 octane rating of 87. We do not recommend the use of gasolines
labeled as "Regular" in high altitude areas that are sold with octane
ratings less than 87.
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.
Fuel quality
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
246
2008 Town Car (tow)
Owners Guide (post-2002-fmt)
USA (fus)