For decades, straight sixes were a Chrysler Corporation (and Jeep) mainstay, powering cars and trucks alike.  The slant six fell first, in 1987 (by then, it was only used in Mexico), followed by the Jeep six , which lasted into 2006.

AMC 4 liter straight six

Now, rumors coming out of Auburn Hills suggest that the company may be looking to straight sixes again. These would, we suspect, be based on the GME four-cylinder design (which has yet to be used in any Chrysler, Dodge, or Jeep, but has been seen in Alfa Romeos).

BMW has continued to use in-line sixes, and Mercedes is developing new ones; they are inherently smoother-running than V-shaped engines, and have packaging advantages in some applications — particularly where suspension articulation is important.

At this stage, we only have rumors, but if the engines are “for real,” we should expect to see them in around five to seven years.