K&N reusable air filters are definitely worth the extra cost upfront, as they are designed to last the life of your vehicle. Fitting a K&N high flow air filter is the easiest, most cost-effective and least technical way to increase engine performance. K&N filters are worthwhile, reusable, and come with a 10 year or 1 million mile warranty. If you've ever been to an auto parts store, you've probably seen air cleaner boxes that claim extra power and more torque than the factory filter.
But being so cheap and easy to install, it's hard to believe that these filters actually produce observable gains. Well, Jason Fenske from Engineering Explained put these claims to the test, and it turns out that yes, high-performance air filters actually produce more power. I've been using K&N filters on my cars for 10 years or so. I'm not sure if they're really worth it, but I've never had a problem with MAF. I should disagree with this general statement. In a normal passenger car? Sure, it's probably not worth it.
However, once you find the need for a high-performance filter, the K&N is an excellent choice. I bought a K&N outlet years ago for my Subaru, and that same filter is still in use and looks new when clean. CRC Sensorklean to remove oil from MAF. A couple of original equipment have it listed as a first step before replacing an iirc mass airflow sensor. I know Chrysler does it for sure.
If you grease the filter too much, then yes, it will damage your MAF sensor and even clog your throttle. A simple solution for that would be to simply not overgrease the filter. How do you know if you're getting too fat? In addition to videos you can find online and tutorials, the cleaning kit describes how to properly lubricate the filter. Find an offer (eBay, Amazon) to drop in and try not to pay full price. K & N itself is decent. But it's almost impossible to clean them well, oil CAN affect the MAF and dirt sticks to the oil, meaning filters can clog more quickly.
If it's for a daily driver, I'd say no. If you're trying to modify a project car, there's no reason not to, but I highly recommend Specter over K & N. You'll never get a big power boost with a cold air intake, but it doesn't sound so bad. It depends on what your goal is. If it's to increase HP, no, it's not worth the money.
If you're looking to eliminate the need to buy an OEM-style replacement air filter every time you make your adjustments, it will take you a few years to get the most out of it. But if you're looking to increase MPG, an air filter that provides increased airflow to your intake manifold while keeping the air relatively clean and free of debris will give you an increase in miles per gallon. It suggests that the increase in power could be the result of less filtering, especially in the case of the cheaper CarQuest filter, although because it had no way of testing the filtering process, that aspect was not observed. It depends on the car, if you already have an air box that is supplied with cold air from outside the engine compartment, it can make things worse if you take it all out and put in a higher flow filter, but drawing air from under the hood. So, if more air produces more power, wouldn't the power increase if I removed the filter completely? Yes, you're right, I would and many do just that. I put in a cold air intake and eventually my car would shut down at the most inconvenient times (i.e.
roundabouts) and it ended up being the mass air flow sensor that failed. The trademarked red filter (usually conical in shape) on display or its kit may include a closed air box. While replacing only the OEM air filter with a K&N high flow filter will add power and increase acceleration, the biggest gains come from installing a complete cold air intake system. I change the air filter approximately every 20,000 miles, and at $10 each time I would have to keep the car for 100,000 miles to make the k&n worth it. If the car is standard, the air filter you have is designed to provide enough air for maximum power. What Fenske doesn't prove is how well each aftermarket filter actually filters the air entering the engine compared to the original unit.
Cotton allows much greater airflow than paper - more air - however it risks allowing contaminants to enter but K&N has it covered - they use their secret sauce: filter oil. I remember reading an article in Performance Ford where they tested the same car with stock, k+n cone, cheapo cone and then drilled 2 inch holes in the air box under the filter panel. It means you have a filter that you can clean and re-grease which is good but some find that they contaminate airflow sensors if a little excess oil is applied so that may be a consideration. So is a K&N high flow air filter worth it? The answer depends on what your goal is - whether you want increased horsepower or improved fuel economy - as well as how long you plan on keeping your vehicle for. If you're looking for increased performance or fuel efficiency over time then investing in a K&N high flow air filter could be worth considering.