Vehicle twist axle assembly

A twist axle assembly for a vehicle, comprising:

• a pair of spaced apart trailing arms;
• a twist beam of a single piece, said twist beam extending in a first direction between opposite ends that are secured with said trailing arms, and said twist beam including a pair of end portions and a middle portion which extends between said end portions;
• said twist beam having a pair of side walls and at least one additional wall extending between said side walls;
• said at least one additional wall of said twist beam having, along an entire length of said middle portion which extends on both sides of and across a midpoint of said twist beam, a constant first width in a second direction that is generally transverse to said first direction;
• said at least one additional wall of said twist beam having, in each of said end portions, a second width in said second direction, said second width being greater than said first width, and wherein said at least one additional wall of said twist beam tapers from said first width of said middle portion to said second widths of said end portions for gradually increasing a torsional stiffness of said twist beam from the middle portion to the end portions;
• and
• in said middle portion, said twist beam being single-walled and having a U-shaped open geometrical configuration as viewed in cross-section.