Need to know your year or wheel size or something???
15 inch and 16 inch are both available factory depending on your year...
For example, in 2002 alone the following are available from the factory.
4 Dr, Sport Trac, (16x7), steel
4 Dr, Sport Trac, (16x7), alum, 5 straight spokes
4 Dr, Sport Trac, (16x7), alum, 5 angular spokes
And for all of the 2002 Explorers (all models) these are available...
2 Dr (Sport), (16x7), steel
4 Dr, Sport Trac, (16x7), steel
4 Dr, Sport Trac, (16x7), alum, 5 straight spokes
4 Dr, exc. Sport Trac; 16x7, alum, 5 double spokes, w/openings in spokes, satin nickle finish
4 Dr, exc. Sport Trac; 16x7, alum, 5 split spokes ID 1L24-SD/SE)
2 Dr (Sport), (16x7), alum, 5 angular spokes
4 Dr, Sport Trac, (16x7), alum, 5 angular spokes
2 Dr (Sport), (16x7), alum, 5 straight spokes
4 Dr, exc. Sport Trac; 16x7, alum, 5 double spokes, w/openings in spokes, sparkle silver finish
4 Dr, exc. Sport Trac; 16x6-1/2 (steel)
4 Dr, exc. Sport Trac; 16x7, steel, 5 spokes, chrome
4 Dr, exc. Sport Trac; 16x7, steel, 5 spokes, painted
4 Dr, exc. Sport Trac; 16x7, alum, 5 double spokes, w/o openings in spokes
4 Dr, exc. Sport Trac; 16x7, steel, 8 spokes (chrome)
4 Dr, exc. Sport Trac; 17x7-1/2, 5 spokes (alum), satin nickle finish
4 Dr, exc. Sport Trac; 17x7-1/2, 5 spokes (alum), sparkle silver finish