Choosing The Right Fuel; Octane Recommendations - Mercury Sable 2004 Owner's Manual

Maintenance and Specifications
If the "Check Fuel Cap"
Soon/Check Engine" indicator comes on and stays on when you start the
engine, the fuel filler cap may not be properly installed. Turn off the
engine, remove the fuel filler cap, align the cap properly and reinstall it.
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.
If your vehicle is a flexible fuel vehicle (FFV), use only UNLEADED
FUEL and (E85) FUEL ETHANOL. 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 additives.
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

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.
204
2004 Sable (sab)
Owners Guide (post-2002-fmt)
USA English (fus)
indicator comes on or if "Service Engine
87
(R+M)/2 METHOD