I realize that this doesn't exist, but I did some rough math comparing the Hemi powered Durango to the HEV Durango and came up with these rather amazing figures.

2009 Dodge Challenger R/T
5.7 Hemi V8 - 5 speed automatic
City: 23 mpg
Highway: 28 mpg
Average: 25 mpg

Granted this isn't exact or anything but it'd be close, the Durango is more of a hog and less aerodynamic so if anything these figures are low.

By comparison a base model Malibu or G6 with the 2.4 ecotec and 6 speed auto does:

City: 22 mpg
Highway: 33 mpg
Average: 26 mpg

Why doesn't Dodge offer this again? Yeah, it'd be more expensive by 3-4 grand but you'd be able to get government cash backs, lower cost on your license and be able to drive in the bus lanes. Not to mention all the money you'd save when cruising around looking cool, which to be honest is what this beast does best.