It was probably an effort to satisfy those who prefers a car-like ride.I have no idea what the Fiat engineers were thinking when they put coils springs in a cummins truck...
It's not a matter of needing leaf springs. Most tractor trailers do very well with air springs, and large locomotives get around fine on coil springs. How those different suspension types are put to use is what matters.Yeah like what has been said you need big leaf springs on the back to help with the weight.
Either way, a late model Ram 2500 isn't a good "foundation" for a camper, for a few reasons.