How much hp does an aftermarket panel filter give?

[interfooler]

I was thinking of changing my stock filter to some aftermarket panel filter like K & N or something. How good is an aftermarket panel filter compared to stock? Why are they better?

[bennjamin]

they will honestly give you 0 hp.

All they will do , however is free up the engine mid range and top end giving you more "pull" than a stock filter. Also more noisy.

Look at K+N , its one of the best.

[aaronng]

Gain is less than the variation in a dyno's reading.
The benefit of an aftermarket filter is that they are washable and reuseable. So you pay $110 upfront for a K&N, but it pays for itself after you changeout 2 OEM filters (which cost $60-70 each). Of course, 2 changeouts mean 4 years. :)

[CB7_OWNER]

You might be better of with a short ram intake or cold air intake.... cost around the same price as a kn panel filter ( if you purchase a generic brand), and if any hp increase will be a minute hp increase over a panel.but you will gain some throttle response for sri