[2004stroke]

I have a 2004 cc 4x4 with the 6.0 that is pretty much stock. I'm pretty easy on the throttle, so I get about 15mpg around town and roughly 18.5 on the interstate. I think these numbers are fine, but I also wouldn't mind getting better fuel mileage if it would be cost effective. I'm thinking about adding a K&N intake ($240) and a Magnaflow muffler (approximately $150). With these two mods, what kind of fuel mileage increases can I expect?

I did some figuring, and if the intake alone would increase my fuel mileage by 1mpg, it would pay for itself in right around a year with the amount that I drive.