According to the 2005 Mercury Grand Marquis Owner Guide : ( 19.0 US. gallons )
In the Gas Tank
owners manual.
on top of gas pedal
For a 2005 Mercury Grand Marquis : " regular " unleaded , 87 octane According to the Owner Guide
According to the 2005 Mercury Grand Marquis Owner Guide ( and one of Fords websites ) The ( Motorcraft FL-820-S engine oil filter is used )
Unbolt it from the floor.
Physically, yes. It would be best to consult an interchange reference to know if the wiring and programming are compatible.
The 2005 Mercury Grand Marquis , 4.6 liter SOHC , V8 engine has ( 2 ) timing chains ( 1 timing chain to each cylinder head )
No
Yes
6 quarts will put it right on the mark.