The 2003 Lincoln Navigator runs on premium unleaded (required).
According to the 2003 Lincoln Navigator Owner Guide : " premium " unleaded gasoline , 91 octane or higher
On a 2002 Lincoln Navigator : ( the electric fuel pump is INSIDE the fuel tank )
The 2011 Lincoln Navigator runs on flex-fuel (FFV).
The 2010 Lincoln Navigator runs on flex-fuel (FFV).
The 2009 Lincoln Navigator runs on flex-fuel (FFV).
The 2012 Lincoln Navigator runs on flex-fuel (FFV).
It is located in the gas tank. Tank removal is necessary.
The 2014 Lincoln Navigator runs on flex-fuel (unleaded/E85).
The 2013 Lincoln Navigator runs on flex-fuel (unleaded/E85).
On a 1998 Lincoln Navigator : The ELECTRIC fuel pump is INSIDE the fuel tank ( it goes in from the top side of the tank )
On a 1999 Lincoln Navigator : The ELECTRIC fuel pump is INSIDE the fuel tank ( the fuel pump is " suspended " in the tank from the top of the tank )