Edmunds did a comparison test of the 2009 F150, Silverado, Ram, and Tundra and found the Ram with the new coil spring suspension towed very well:
We knew from previous experience that the Ram's coil-spring rear suspension works well when the truck is unloaded, but this time we found it has the chops to handle a trailer, too. The superior lateral stiffness of a five-link rear axle and a rear antiroll bar keep things from getting all swimmy while towing, even when we're late for lunch and with a winding road between us and a burrito plate. Later, the burritos stayed down because the Ram 4x4 is best at smoothing out washboard tracks and putting the power down in sand, as you don't get the insistent rear-axle hammering of leaf-spring rear suspensions.
And the Dodge does better over the long haul up the long grade, where the horsepower and the axle ratio come into play. It clears the top in a virtual tie with the Tundra (12 minutes, 51 seconds) and never once needs full throttle — this from the truck with the lowest advertised tow rating (7,300 pounds) in the test.
Dodge for some reason initially advertised a lower tow rating than the others, but this (from what I understand) was just an attempt to steer people into it's heavy duty line.
