Our work truck is a E350 with a 5.4 v8. Great truck, bought with 99k on it for $6000. Ex Ore. St. transportation vehicle- the used vans I looked at from fleet sales were all hammered, the companys buy them, do not put a nickel of maintainance in them, and sell them as soon as they are depreciated out. In contrast, since they are spending our dimes, the state changed the oil every 3k, radiator and transmission fluids, etc. I know cause I was able to get the records. This thing gets about 18 mpg on the highway, 16 combined city/highway.
The 5.4 gets great reviews as an engine, and I beleive the 6 is an 8 sans a couple cylinders.