2003 Navigator: Schaeffer's 5w20, Motorcraft Filter
2002 Accord: Schaeffer's 5w20, Wix Filter
2001 Grand Marquis: Amsoil 0w20, Motorcraft Filter
1985 Z28: Valvoline VR1 20W50, Wix Filter
Reasoning: Recommendations and experience. I always run Motorcraft filters on the modular engines, the anti-drainback valves on these filters work well and they are reasonably priced. Wix filters also seem to do a fine job for the money, I run them on Honda and Camaro with good results. As for engine oil, I usually run some sort of premium engine oil. I have had good results with Amsoil in the past, and recently started an experiment with Schaeffers. The Valvoline in the Camaro was the first fill after some engine work, I will probably change it to some sort of synthetic prior to the next season.