I'm thinking of trying a drop-in K&N filter in my 13 Corolla S. In all 3 of my older Corollas are after market filters. But I've never tried K&N drop-in yet.
AE86: After market air cleaner (caburated)
AE82: After market cone filter
AE92: After market cone filter with custom intake piping
I have noticed a power and fuel mileage difference in all 3 them.
My question is, would a drop-in K&N filter be just as good or better than aftermarket cone? I understand every vehicle will take it differently than otheres. Any knowledge would be appreciated.

Waste of money

A drop in filter is hardly ever a waste of money.

Application dependent. Some cars have a restrictive filter, others don't. 2 examples are sitting in my driveway. My truck's stock air box and filter are not a restriction at stock power. Throw a tuner on and you need an intake. My trans am has a purolator filter with an aftermarket air lid. The housing, MAF, TB, and Intake manifold are a restriction but the filter is not. The old paper filter is good to over 600hp, dyno proven. A K&N or similar drop in will only make it faster by lightening my wallet.


OP, do some model specific research and you will find out if your factory filter is a restriction. Odds are it isn't. It's more likely the entire intake setup is a restriction. Any type of aftermarket intake solution will be for looks and sound. Any real fuel mileage increase will be minuscule and you would have to drive hundreds of thousands of miles for it to pay for itself.

There are 3 reasons to do it.

looks and sound

Planned future mods

Better filtration


if your intake is a restriction and you plan on doing other power mods in the future while staying naturally aspirated it makes sense


If you buy a setup with a cone filter that has something like the AMSOIL dry synthetic media filter it lasts longer and filters better than most stock filters. Whatever you do, stay away from oiled cotton gauze filters like the K&N and others. The dry filters are better technology and there is no oil to foul you sensors.

K&N filters are junk

Thank you for the great information. I'll be doing my research before going through with it. I did find a full after market intake and cone filter for $190. But I'm not sure if that's would void warrenty right? I was feeling towards drop in because; cheaper, and brands like K&N claim it won't void warranty.

Good information but a drop in filter, when appropriate, will pay for itself quicker than you think. But it's hard to calculate accurate mpg gains vs cost because it's so inconsistent.

I bought the k & n drop in for my car and I was just happy to take out the piece of shit egg carton filter they put in there.

This post was edited by stupidkid282 on Feb 25 2015 09:18am

$190 will buy a corolla a lot of gas

This lol
Paper filter and call it a day

I'd at least wait until it needs to be replaced. Didn't you just get the car? When was it last replaced?

This post was edited by CarsAndKush on Feb 25 2015 10:57am