Joined: Tue Oct 11 2005, 01:33AM
Location: Calgary, Alberta
Posts: 5893
My '06 Jeep has the 5.7 hemi, but it has the variable displacement feature that allows the engine to switch back and forth between 8 cylinders and 4. I don't see much difference in the stop and go city driving, but it makes a whale of a difference on the highway if you have a steady foot. It works best in cruise.
I have a 2007 Jeep Grand Cherokee SRT 8 that I bought new. When it was broken in, it got about 8 mpg in town and maybe 16 mpg on the hiway. After installation of a CA intake, new high capacity fuel injectors, a performance exhaust, and a custom Diablosport tune it will bury the speedo at 300 kph, do 0-60 in 4.09 seconds. It now gets about 6.5 mpg in town and 12 mpg on the hiway, less if I put my foot into it.
