fuel additives Mercury Grand Marquis 2003 Owner's Manuals

Engine oil and filter recommendations
Look for this certification
trademark.
Use SAE 5W-20 engine oil.
Only use oils “Certified For Gasoline Engines” by the American
Petroleum Institute (API). To protect your engine’s warranty use
Motorcraft SAE 5W-20 or an equivalent 5W-20 oil meeting Ford
specification WSS-M2C153–H.SAE 5W-20 oil provides optimum fuel
economy and durability performance meeting all requirements for
your vehicle’s engine.
Do not use supplemental engine oil additives, cleaners or other engine
treatments. They are unnecessary and could lead to engine damage that
is not covered by Ford warranty.
Change your engine oil according to the appropriate schedule listed in
the scheduled maintenance guide.
Ford production and aftermarket (Motorcraft) oil filters are designed for
added engine protection and long life. If a replacement oil filter is used
that does not meet Ford material and design specifications, start-up
engine noises or knock may be experienced.
It is recommended you use the appropriate Motorcraft oil filter (or
another brand meeting Ford specifications) for your engine application.
2003 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Maintenance and Specifications
201

Cap light on, can activate the Service Engine Soon warning. When the
fuel filler cap is properly re-installed, the light(s) will turn off after a
period of normal driving.It may take a long period of time for the
system to detect an improperly installed fuel filler cap.
If you must replace the fuel filler cap, replace it with a fuel filler
cap that is designed for your vehicle. The customer warranty may
be void for any damage to the fuel tank or fuel system if the
correct genuine Ford or Motorcraft fuel filler cap is not used.
The fuel system may be under pressure. If the fuel filler cap is
venting vapor or if you hear a hissing sound, wait until it stops
before completely removing the fuel filler cap. Otherwise, fuel may
spray out and injure you or others.
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.
Do not use fuel containing methanol. It can damage critical fuel system
components.
Your vehicle was not designed to use fuel or fuel additives with metallic
compounds, including manganese-based compounds containing MMT.
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.
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 dealer or a qualified
service technician to prevent any engine damage.
87(R+M)/2 METHOD
2003 Grand Marquis(grn)
Owners Guide (post-2002-fmt)
USA English(fus)
Maintenance and Specifications
213