2007 Jeep Commander Hemi 5.7LThis
page is going to be about my wife's SUV. It's pretty much
completely stock at this point. However, I'm slowly and sneakily
assembling parts to do an exhaust swap on it - using the Grand Cherokee
SRT Headers, Midpipe, and some of the cat-back exhaust, I'll be able to
free up the airflow significantly. People doing it to the
standard Hemi Grand Cherokee's (not the SRT version) report a
significant horsepower gain - up to 30hp at the wheels,
as well as a noticable bump in fuel economy. The fuel economy
increase is due to the way the Jeep/Chrysler ECM is programmed - it
runs a cylinder deactivation routine anytime the throttle is below a
certain threshold, and the speed is above a minimum level (usually
25-30mph). With a significant amount of torque gained through the
free flowing exhaust, the throttle input is reduced, allowing the ECM
to go into cylinder deactivation mode, and remain there longer!All original material on this page is Copyright 2015 Brad Jelinski.