5W-30 ( according to the 1998 Lincoln Navigator Owner Guide )
On a 1998 Lincoln Navigator : The thread on cap on the engine coolant reservoir is the pressure cap / radiator cap
According to the 1998 Lincoln Navigator Owner Guide : ( " regular " unleaded , 87 octane gasoline is used )
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 1998 Lincoln Navigator I believe it is in the front passenger footwell ( it might be behind an access panel )
You can view the 1998 Lincoln Navigator Owner Guide online at : www . motorcraft service . com ( no spaces ) Click on Owner Guides
6x9's
According to the 1998 Lincoln Navigator Owner Guide : ( 5W-30 , 6.0 U.S. quarts with engine oil filter change )
According to the 1998 Lincoln Navigator Owner Guide : With engine oil filter change : ( 6.0 U.S. quarts )
According to the 1998 Lincoln Navigator Owner Guide : ( 30 U.S. gallons )
According to the 1998 Lincoln Navigator Owner Guide : ( " regular " unleaded gasoline , 87 octane )
because you own it