K&N Air Filters Can Save You Money

Recently I ran across a sale on K&N auto filters advertised on the web.   The company K&N Engineering sells the K&N filters.  The replacement filters from K&N are supposed to improve air flow while still filtering the air efficiently.   This should help improve performance and horsepower.   The filters are also reusable.   I've heard about this kind of filter before and had a vague idea that they should save you money but I wanted to take a closer look.

Are there MPG improvements?
 Some people believe that these filters improve MPG but the actual impact to fuel economy is unclear.  K&N doesn't directly claim or boast of increased MPG.   Personally I think if the filters did really increase MPG then the company that made them would be bragging loudly about it.   Some users claim they have improved MPG.  For example this article claims a 0.5 MPG increase on a truck.   The governments Fueleconomy.gov site  cited a study that found with new fuel injected and computer controlled engines that a clogged fuel filter shouldn't matter but for an older carbureted car the clogged filter did impact MPG.   Since there are mixed opinions on this I wouldn't count on MPG improvement.


Cost benefits of reusable vs disposable
I can buy a K&N 33-2260 Replacement Air Filter off Amazon for my Toyota for about $28.  A cleaning kit costs about $11, the cleaning solution is supposed to be enough for 5-10 uses.   The FAQ on the K&N site says that you should only need to clean the standard filters once in 50k miles.   So you're talking about $40 for a filter and cleaning kit that should last the life of your car.   

A standard disposable air filter would cost $10-11 on Amazon or NAPA.   The typical paper filters are supposed to be replaced every 10k to 15k miles.

Lets say you operate your car for 150k miles and the disposable filters last 15k miles each.  You'd need 10 disposable filters at a cost of about $10 each for $100 total.  The reusable K&N filter would cost $40 and last as long.    The reusable K&N filter could save me $60 over 100k of driving.   Now keep in mind this is just one example and the air filter costs vary depending on the make of the car in question.  

What do customers think?
I found a few sources of reviews of the K&N filters.   Amazon reviews for the 33-2260 model were good with 13 reviews and over 4 stars.   The33-2031-2 model had 23 reviews also over 4 stars.  The site Car Review had over 100 reviews for K&N filters with average score of 4.1 out of 5.  Thats pretty good review averages.   Generally the reviews I find for K&N filters are quite good.

Bottom line the K&N air filters seem like a good deal.   They have some solid benefits in increased performance and lowered costs plus some pretty happy customers.   But I wouldn't count on an MPG increase.

[edit: I forgot to mention that I have not used K&N filters myself]