Car Air Filters

review by a car ignoramus
I know nothing about cars. Okay, very little about cars. But this looked a darn sight more sturdy than the one I took out, and I didn't have any trouble figuring out how to put it in. So as far as I'm concerned, this gets a thumbs up. I haven't yet tried to clean and reuse it.

some fuel economy benefit
I have had K&N air filters in my cars in the past. Usually, I have felt a performance advantage and a fuel economy benefit. With this one, I noticed about 1 mpg benefit, bu no performance advantage. It is also a lot more flimsy than I have seen in the past. K&N must be cutting costs and using cheaper materials. Still worth it if I keep getting better gas mileage.

Typical K&N filter, only so so...
This is one of many K&N filters I have purchased. I buy K&N filter for its reusability rather than its claimed performance boost. All previous K&N filters I have installed shared a good quality trait, reinforced structure. This one is different! I am wondering if it is made by the same manufacture or faked by an unknown factory in rural China. Not only lacking supporting material on the filter part, this product has an extremely sloppy frame compared to the OEM filter; thus making it harder to install as it flexes too much. After installation, this filter showed little to none increase on either gas mileage or horsepower compared to the 40k-mile-old factory air filter.

For me, I am still getting the reusability of the air filter...I hope. At the same time, I am a bit nervous about this product due to its sloppy structure. Is it going to hold up after next clean and renewal process? I am not sure although hoping for the best.

Not much of a difference
The filter promises more horsepower and improved mileage. From my standpoint, in my car, there is no noticable improvement in acceleration, from a performance standpoint, it seems to be the exact same car.

As for mileage, I was averaging 25.x MPG before the filter in mixed (highway/city) driving. This has improved to 26.x MPG, so on average, I picked up between 1.0 - 1.5 MPG, so that was nice.

The longevity of the filter is appealing and since it will be a while before it needs to be cleaned, I can't comment on the maintaining the filter. I will likely buy a MazdaSpeed 3 before the filter needs to be cleaned.

Insert, Forget About It, Don't Bother Cleaning It
These air filters are high quality cotton impregnated with a special oil that traps dirt and dust without compromising the air flow. They seem to work well, but I'm not sure my mileage increased any as some people claim. You definitely want to run higher quality oil in your car and make sure to never miss a filter change because this thing apparently lets through slightly more dirt than a paper filter would.

I ran a K&N in my Mazda Protege and, after 50,000 miles, bought the cleaning kit and followed the instructions to the letter. Cleaning is messy, oily, and inconvenient. It might take a day or two to dry naturally (K&N says not to blow dry it or dry it in direct sunlight) so you have to either not drive, or use a paper filter in the meantime. For the price of these, I just decided to throw them away when they hit 50,000 miles and get a new one.

You also definitely want to use the sticker that comes with the filter. This sticker goes on the air box of your car and instructs mechanics to NOT replace the filter. You can lose your expensive K&N if Joe Badwrench changes the air filter without you knowing it!


I think this is a good deal simply because it works through its promised lifespan and it keeps me from having to change something every 5000 miles. I'm willing to pay a premium for convenience! Just remember to change the oil regularly!

OEM fit for my 2005 Mazda 3 2.0L
Came factory oiled and slipped right in where the original factory filter came from. I have to admit, changing the air filter in this car is a pain in the butt. Thankfully I'm set for another 25K miles. When cleaning and re-oiling the filter, I will be picking up the aresol version of the oil, as I hear it takes 1/4 of the time to re-oil versus the drip type of K&N oil.