My '97 had the 4.6 in it...towed nice, but felt it wasn't enough. Bought the '00 with a 5.4...towed a powerwagon (5500lbs) with a 3 ton trailer for 7hrs...not a problem...
When we went to look at the '01, we couldn't turn down the deal so we bought an '01 with the 4.6 in it. I've towed with this truck my 3ton trailer loaded, but not fully loaded. It towed fine in the White Mountains and Green Mountains...
I don't tow that much anymore, so it wasn't worth having the 5.4 in the Expedition when the 4.6 does fine. Guy(NH)