I have an 05 dodge ram quad cab 4x4 with the 4.7 when I first got the truck I got 14 mpgs. I put a k&n air filter on it started using castrol synthetic oil and now I get 19 to 20 mpgs and that aint bad for the size of truck that it is.
I have a 97 sport with a chipped 360. I think the bigger 360 instead of a 318 really makes a difference. That engine doesn't even break a sweat at 60mph. 1200 rpms to be exact. The chip adds about 3 to 5 mpg. I also run a strait pipe. If the engine breathes better, it performs better, thus resulting in better gas milage. And it sounds bad assed!! The police never bother me, because all Dodge trucks sound bad assed!!! By the way,22 mpg.
I drive an '01 with a stock 360, automatic (bought it used, would have preferred a stick), and 4x4 with 3.55 gears. I put in a K&N air filter, and installed a Thrush turbo muffler. I also have an aluminum cap. I'm getting right around 20 MPG. The main thing I do is to keep my foot out of the throttle. I drive this one like my old single-barrel six-banger.
By the way, I neglected to mention that I use all synthetic lubricants and fluids in my drive train. Additionally, I use Lucas oil additives in all my fluids (engine oil, tranny fluid, differentials) and I use Lucas Upper Cylinder Lubricant and Fuel Treatment religiously.
Yeah, the 360 has always had a track record of getting better mileage than the 318. I'm not certain, but I think the only real difference is the stroke (I think they have the same bore).