Replacement filters and air intake systems from K&N can also increase engine horsepower. While many air filters cause an increase in gas consumption, the manufacturer's have been found to improve upon it in some cases if all other factors are contributing to the same effect. It stands by a Consumer Protection Pledge and also offers a Million Mile Warranty on its products. The company is consumer-centric when it comes to selling its products. There are, in fact, over 5,000 products sold by K&N for various types of vehicles, including cars and trucks but also motorcycles, industrial machinery, and engines in general. The company invented a high flow cotton air filter, back in 1969, and continues to produce washable air filters for automotive air and oil applications. It is considered a world leader in these products. For now, I'll keep running my K&N and not worry about it.Primarily a manufacturer of performance air filters and air intake systems, K&N is located in Riverside, California. All I know is I don't think I've ever gotten over 20 mpg before.

Maybe my improved gas mileage was all in my head. I've pretty much found 2 sets of people, the ' oh my god its going to ruin your engine (or so I heard)!' crowd and the ' I've ran K&N filters for the past 10 years and haven't had a single problem' crowd. Since I posted this thread and got the replies that I got, I've scoured the net looking for info. Take his tests for what they're worth.some guy doing his own tests in an uncontrolled environment with debatable results.ДЄ guy in this thread ( ) says he drove a CRX for 494,000 miles with a K&N filter in it. He also goes on to say that cotton gauze is the best for airflow and paper is the best for filtration. Per his tests, a K&N cotton gauze filter is superior to an Amsoil foam filter for both filtration AND flow. These filters won't double your gas mileage, but with prices the way they are now, every little bit helps.Д¬lick to expand.Not based on what this guy says: And I definitely plan on keeping this truck until it dies, which could be a couple hundred thousand miles from now (I currently have 53K on it). I only need to keep my truck for another 80K miles before I've saved money simply on filters, let alone gas. These filters are guaranteed for 1 million miles and all you have to do is clean them once every 30K miles or so. This thing is, I will never buy another filter again. I paid $60 for the filter and recharger kit, whereas a typical filter for my truck runs around $15-$18. The initial investment was a bit more than a regular filter. I won't know what my true highway gas mileage is until my next road trip, but I can guarantee that it'll be higher than 20.5 mpg. And that was driving apprximately 60% highway, 40% city. This morning I filled up for the first time since installing the new filter. Last week I went out and bought a K&N air filter. Up until now, the best gas mileage I ever got was around 19 mpg, and that was 100% highway. These filters are different than your typical air filter and allow a lot more air into your engine, increasing both horsepower and gas mileage. For all those that want to save a little money on gas, here's a simple thing you can do to increase your gas mileage without much effort: Go to you local auto parts store and buy yourself a K&N air filter.

How to clean a k and n filter