You can't really force gobs of air into the system though on a daily driver with a CAI. Throttle Body Valve is going to let in just as much air as it would with a factory air intake unless you are running wide open throttle all the time (which if you are trying to save money at the pump is not exactly smart). At least that's my understanding. Again, CAI on my truck and never got any extra power out of it or noticeable throttle response. And by the time you spend money on a more free flowing exhaust, you're out more than you would have been in 5 years at the pump (might be slightly exaggerated on the 5 years, but seriously....) Best thing to get better mileage is to get a tuner with a live trip econ calculator on it so you can actually see what your truck is getting with your foot on the gas pedal and adjust Gods mechanics on the bottom of your leg accordingly. You'll save money over getting a full on free flowing exhaust (because just getting a muffler and some custom pipe after the cats isn't going to be enough to get a noticeable increase) and will be learning how to squeeze out the best MPG's in your pig.