TankJ11

I have an 08 V6 Premium I just bought, manual, with the single exhaust.

I want to make it more powerful, but still keep the good gas mileage...I'm already thinking of dual exhaust, but is that gonna change my gas efficiancy?

Also, wondering what kind of air intakes, gas injectors, and other easy things I can do to add a few hp's.

jimkaray

The best bang for your buck is to upgrade to a GT take off muffler, preferably from a manual trans car. The GT muffler will give you a little bump in performance along with improved sound and looks. Duals aren't going to make any more power or gas mileage to speak of than a single GT or free flowing muffler will provide. Consider duals a cosmetic mod until you start upgrading to some major power adder mods.
Next up get a custom tune with a CAI /larger MAF package. This will provide you with a very noticeably performance increase and improved gas mileage depending on the tunes you choose and how you drive the car. First check out the 4.0L specific forum and start with the sticky for info on popular tuners and pleanty of threads on exhausts, tunes, gas mileage, etc.

my94pony

buy a tuner then do your mods in mind because u need a tuner for anything u do on the s197's