According to the 2000 Lincoln Navigator Owner Guide :
( 5W-30 engine oil is used )
With engine oil filter change , 6.0 U.S. quarts / 5.7 litres of engine oil
5W-20 is the OEM recommendation for Ford products with gas engines.
4.6 litre
JFK was shot in a Lincoln convertible, manufactured by Ford Motor Co.
R134a
Any SAE approved 5w30 motor oil will work just fine in your Towncar. If you have a lot of miles on it you may want to consider one of the new high mileage blends.
On a 2000 Lincoln LS : The FRONT suspension is a strut type suspension , so there are ( NO ) upper ball joints
2.0L 4 cylinder
5w30w
Engine oil recommendation's in the owner's guide is Motorcraft SAE 5W-30 Super Premium Motor Oil, Ford specification WSS-M2C153-G
The 2001 Lincoln Town Car Owner Guide shows ( 5W-20 )
( 5W-20 ) according to the 2003 Lincoln Town Car Owner Guide
10w40 mobil1