I went with the flowmaster super 40 and I like the sound. It is also a lot smaller then the stock one. It did not help the mpg but the pickup is a little better, before it would kick down 2 gears when passing, it only drops down 1 gear now and has enough power to pass, but it's no race car......lol
Rob

 

I like the way my Borla cat back sounds, not sure about the power, since I have added much bigger tires. Here is a sound clip:

http://www.youtube.com/watch?v=39gf3DvAHeQ

 

Here's the best information that I have so far:

Link to the only dyno results that I've seen. This is the system that I modeled my kit after. 1BADJK DYNO TESTING

In case you care about sound, here's a link to some testing that I did. BORLA, MAGNAFLOW, FLOWMASTER SOUND VIDEOS

A note that I received from one of my customers, about mileage. These are real calcs, not the computer stuff.

My mileage numbers for the last 6 tanks of gas:

PreMuffler Kit
1. 10.85 MPG
2. 11.75 MPG
3. 10.26 MPG (Top off the Jeep)

Average: 10.96 MPG

PostMuffler Kit
1. 12.93 MPG
2. 11.93 MPG
3. 11.29 MPG (Top off the Jeep)

Average: 12.05 MPG

So, I'm seeing a 1.09 MPG increase right now. I will continue to track it as I think the increase is closer to 1.5 MPG.

Jeff

 

dont feel bad brett im only getting 11 on a good day with the wind pushing me and going down hill lol

 

I have a flowmaster super 44 and I love it...saw a noticable difference in mileage...around 1mpg better on average.

 

Just got the Banks cat back off of 4wheelparts.com for $283.99 (2 door) shipped to my door. They are running a special for $75 off.