[CREWZIN]

Dan,

Lots of pros & cons from owners on that question. I have one like you see on eBay but the guys that are after every ounce of power from their 4 banger say that the open element filter draws in too much hot air from the engine, thereby decreasing HP. The more costly open air elements like Volant, K&N and Air Raid put the filter in an enclosed area to ward off the hot air. Some say you can't do better than the stock air filter box with modifications to let it breathe better ie: K&N filter, larger snorkle, removing white rings.

All the aftermarket filters make it a little bit more noisey as you can hear the air rushing in when you have your foot to the floor. Some have said they've seen an increase in MPG by 1 or 2 miles.