[muns53]

Rather than dropping serious coin on an aftermarket intake, I elected to go the DIY route, figuring if I hated it, I was only out $50.00.

There are plenty of "how-to'" on the diesel sites (powerstroke.org has a good one), so I won't reinvent the wheel describing it. But all that's needed is a 3-4inch piece of 4" OD alum pipe, a great big Duralite or NAPA#6637 air filter and a clamp. With the stock airbox removed, it just sits in the space just behind the battery. Then, I drilled a bunch of various-diameter holes in a cool pattern in the front for the "Zoodad mod" - opening up air flow a bit more in the front. Then, I bought and installed a 4" turbo-back alum exhaust with a straight-through muffler from Diamond Eye.

Mileage:
I went from 13 mpg to 16 mpg average - and that's winter mileage - calculated, not relying on the computer. On short highway trips (65-75 mph), I do even better; averaging around 18.

Performance:
I think it has more juice and I know it's getting better airflow b/c I can hear it. I feel it spool faster, so the power comes on faster; and I cruise with lower RPMs, so I know it's better across the whole band.

Hope that's helpful!