Originally Posted by Sahara Lee

Copied over from another thread:

As with the military, when the government dictates how a company is run, cost effectiveness gives way to the whims of politics. Right now car companies are struggling to meet present and future Corporate Average Fuel Economy (CAFE) standards. Although full independent suspension is more complicated, more costly and more failure prone, it is lighter than a solid axle therefore it will be in our future if the Jeep fleet is to get 54.5MPG by 2025. Assuming there is not a major revolt by voters between now and 2016, major effects of CAFE will start kicking in for 2017.

Obama Announces 54.5 mpg CAFE Standard by 2025 - Popular Mechanics

As far as fully independent suspension, that has been the military standard for jeeps (not Jeeps) since 1959.

M151 (MUTT) was produced by Ford, Kaiser and AM General from 1959 to 1982 and saw military service at least until 1999 has fully independent suspension and unibody:
YouTube Link: http://www.youtube.com/watch?v=giqGHuWv-eM

And was replaced by the AM General HMMWV which also has full independent suspension:
YouTube Link: http://www.youtube.com/watch?v=_S7zhTkVepw

Originally Posted by Tooadvanced

But it isn't lighter at all. Just watch car shows on weekend. They swapped a irs onto a ranger and it was about 40lbs heavier. Not a big deal since it was rear wheel weight on a truck with 700hp but still ifs/irs is heavier