All of these air filters are direct replacements for the stock air filter box, its hard to choose which one to get. These are all the available options at O'reilly auto which is local for me. Mine is a bit dirty and I would like to squeeze out as much mileage as I can. If you have a recommendation not on the list please also share it.

8.99 MicroGard
13.99 WIX
13.99 Fram - Tough Guard
12.99 Fram - Extra Life
11.99 Fram - Extra Life
19.99 ACDelco
34.45 Speed by Spectre
44.99 K&N Engineering

I am also considering a K&N cold air intake, and I understand the importance of no engine air making it to it. So I would build a box probably out of corrigated plastic like those "VOTE FOR ME" type signs. I have built a box like this before for a small car that kept the engine air away and duct the cold air to it.

 

wow I was thinking same thing still checking prices one idea K&N filter alone, just replace the filter. Where I'm at laws are real stiff about it so it affects the price. Some dude tried to throw me a meat ball and said 500.00 Be careful good luck and keep me in the loop I have a couple of pictures of the cold air intakes on my page in my albums check them out?? Take care.

 

I have the drop in K&N.

 

Wix is a very good filter.

 

wix makes some good paper filters. I have a k&n myself. A little worth 50 bucks. I gained .6 mpg,so its gonna take a while to save money.

 

I had a K&N but all the dirt and dust from going off road would clog it up to easy since its oiled. So i got rid of that and now have a ACDelco off-road duty filter. It is basically the same as a normal delco filter but it has a foam type piece that the air has to go through first. Its like a pre filter for the filter

 

I use K&N drop in filter for my 1st & 2nd gen blazers and in my Subaru. Reason: More air flow. Depending on your driving style helps with fuel economy as well.

 

I used K&N drop in for awhile. I think the best gas mileage i got was 21-22 mpg's. I just recently bought and installed Spectre CAI kit. Havent had a chance to check mpg's yet. The Spectre kit was IMO a good deal. I got it from streetsideauto.com for like $100 delivered. The kit comes with everything from cone filter to intake tubing and clamps.

 

I like the K&N because it has a lifetime warrenty and when it gets dirty just wash is off oil it up a little bit and stick it back in, no more replacing filters

 

Well im thinking I may try the k&N CAI