K&N High-Flow Original Lifetime Engine Air Filter: Increase Power: Premium, Washable: Compatible with 2005-2020 Scion/Subaru/Toyota: FR-S, TC, BRZ, 86, Corolla, GT86, 33-2300

Great quality, easy to install.

Very easy to install. I have a 2017 BRZ with 1,000 miles at filter change. Before install keep close attention to the how the old filter is positioned, because 3 corners are rounded, and one corner is L-shaped. The K&N filter also has one corner L-shaped so position that corner on the same side as the original. I watched a lot of YouTube videos on how to install, but it came down to unclipping the 2 clips on top, open the rear cover as far as it could go, removed the manufacturer's filter, checked the cleanliness of the inside of the intake tube area, and slid the new K&N filter in. The opening was wide enough, and I was careful not to damage any tubes, wires, or sensors. Made sure the gasket of the new filter fit within the grooves of the housing. The K&N filter is lined with oil so keep it in the plastic until you are ready to install.I have no access to a dyno - so no way to measure HP gain; otherwise unnoticeable. However, there is a noticeable gain in throttle response. I also noted my mileage before install at 33.5 mpg, and after driving for 2 days with the new filter I notice the average on my dashboard display was 34 mpg (no change to my driving routine). I am getting higher avg. mpg's, because I am not running my AC since outside temps are still quite comfortable.

Its a reusable air filter the gives a few HP gains (according to the dynos floating around the web). The power likely isn't that noticeable. I installed mine in my 2017 BRZ. There is a deeper growl at the top end of the RPMs. These pay for themselves after a couple washings compared to buying new filters so why not. We get too much rain and flooding in South Florida to risk hydro-lock with a cold air intake. This is a great compromise.Be aware, the install is slightly more difficult than I've seen in any other car or bike. With this filter/application, you need to take the whole air-box out of the car, separate the clam-shell box and slowly and patiently work this filter into the box while closing it. Be very careful the filter doesn't bow in the box and create a gap at the bottom where dirt and debris can work itself into the engine. There is a thick rubber skirt around the filter that seems to be a half-inch too big for the box all around. That's apparently normal. Be patient and don't hesitate to start over if you think it does't fit right. You'll know when it does. And you can check through the snorkel hole (dirty side) to see how well the filter is fitting inside the box.

Installed in SCION FRS for the sound. Personally, I felt the lack of engine/exhaust sounds from the car really took away some of the experience.The driving dynamics of my car changed, specially the throttle response, noise and torque...it made THAT much of a difference. Going into first gear, I used to give it more juice, but now it just roars and wants to go. First time, I let out the clutch quickly, the tires just started spinning, it's never done that before. There is less lag at lower RPMs and the car just wants to go. Even sounds like its taking a lot more air than before. This is not placebo, because I am still having getting used to it after a day of driving. Even the engineer doing maintenance on my car was not used to it before and after. I remember standing at the shop and he press the throttle like he normally would and it let out a good sound.HP, I did not notice, but was gonna install my catback...after I got this, I thought, I'd wait and enjoy the engine sound a bit longer by itself. What a great and cheap mod. Only had it a day, been driving it hard, so no idea on mileage, but who cares? I am extremely happy with this filter.Downshifting, meh, a little more sound and didn't notice too much throttle response.

Always a known quantity

Hey DIY folks, buy one of these and you'll probably only clean it, never replace it. Love K&N products, they have never let me down. Meanwhile, the Perrin filter I bought that was supposed to last and last, failed as it's put together with foam and spray glue. Just wore itself out over time and cleanings, the glue joints failed. K&N filters are molded, big difference.

My 2005 scion TC is the third vehicle in which with a K&N filter was installed.As other reviewers mentioned above, this is a good filter with somewhat less restricted design for improved airflow. It's most important feature is that you can clean and maintain it as often as you want without having to replace it.You simply cannot expect a high performance gain from a filter installed in the stock filter box, in a stock, low-rev engine. Yes, it sounds better at high rev and maybe adds a couple of HP, but that's not really noticeable in an engine with 160HP to boot with. Even a CAI would not benefit that engine that much - not without a proper ECU remap. With that combo you might be flirting with 2 digit gains (like 10% best, with a good mileage penalty tho).So buy with confidence that this filter is not magic...4x stars exactly cause they exaggerate a bit in their site about performance gains...

My car has a stage 1 93 octane tune from openflash tablet however after and while installing this filter I noticed a few things:1)Throttle response slightly quicker basically a light throttle tap responded slightly quicker than the OEM filter2) slight sound difference at low RPM, in the lower rpm range (under 4k) the engine sounds smoother and resonates a bit less in the cabin3) the design of this filter is way better side by side than the cheapo cotton like denso filter into the car stock, this simply looks and feels like it filters more contaminants out efficiently4) As for horsepower increase that's negligible I noticed none other than a throttle response increase its a drop in filter anything under 5 HP is expected any more and its a blatant lieAll in all its a great buy although some of the claims can't be really substantiated without a dyno but there is slight differences you can feel for the better