[JohnM]

Wow - I didn't expect this benefit. My gas mileage seems to have improved by over 20% with the addition of the 3 inch downpipe and CAT. Admittedly this is after just one full tank since adding the downpipe, but that first tank is almost 2 mpg better than my best ever. I have averaged about 17.5 mpg over the life of the car with combined daily driving. I've checked almost every tank in 10K miles, and it's usually between 16.5 and 18.5. Best ever has been just short of 20 mpg and it's only been near there a couple of times. First tank with new downpipe is 21.8!

BTW - I noticed no increase in mileage with just the addition of the 2.5" Mopar/Borla cat back system before I added the downpipe.

I've got the Maxxfab downpipe from Scottmech. See his post in the Vendors area for pictures of my car with the pipe.