My family has/is owned all 3 of these engines. I'll start with mine, 4.6. Decent low-end torque, but could use alot more, doesnt get good pull til around 3000. My dad has a quad cab 4.7 2WD, mileage stays around 18, this engine likes to rev not alot of low-end, from about 3000-4000 pulls pretty good, sounds like a car engine to me. Last of all the Chevy 4.8, as with the 4.6, I think its a bulletproof motor, ours went 143,000, never skipped a beat, it was in a 4-door 4x4 chevy. On a trip to Va. we averaged 22mpg on the freeway. Before you start saying "these engines dont belong in trucks", look at the buyers intended use of the truck, probably just wants something that will function occasional 4x4 use, mostly highway work. The only gripe I have is with the 4.6, I see 5.4s getting same or better mileage as the 4.6, so really there wouldnt be a benefit to getting the 4.6