Well, it ain't. When I worked for the local Chrysler dealer, that was the number one complaint. Poor fuel mileage. There were also several TSBs issued, so, Chrysler was aware of the problem. ....and to the OP, I never said the 4.7 wasn't a good engine. They are ok. It's just that a properly prepared small block will get better mileage. What I'm interested in is how you're gonna get the computer system for the 4.7 to work with a 904. heck, I'd use the A500 even with the floorpan mods required. Overdrive would be cool.