Do Performance Air Filters Actually Work?

hello everyone and welcome in this video sponsored by RetailMeNot we are going to be doing some very cool testing so the question is do performance air filters actually work and so I've got four different air filters here in front of me we're gonna put each one of these in the car on the dyno look at horsepower and torque and then we're also going to be doing real-world testing using this v box to see out on the open road do any of these air filters actually improve acceleration okay so first let's get into the filters which we're going to be testing so the very first one is the dirty air filter that was already in the core this is an original equipment filter as you can see it's filled with bugs grass dirt that kind of stuff and so our baseline will be done with this original equipment filter dirty spending the car for maybe three is six thousand miles and accumulated a good number of bugs in there the second filter we will be testing same as the first one the only thing is its brand new it's clean there's nothing in it yet so brand new OE filter which will be then testing after testing the dirty filter then we move on to our low cost option this is a CARQUEST filter which I found online lower price point than the OE filter so we will see if there's a difference between this lower cost aftermarket filter versus the original equipment filter it does say premium there on the box and finally we have our high-performance highest cost filter this is a K&N filter which says right on the box that it is designed to increase horsepower and acceleration so we will be putting those claims to the test does it increase horsepower we will test that on the dyno does it increase acceleration we will test that out in the real world using the v box so before we get into the testing I want to explain very quickly why a high performance air filter might actually increase horsepower and so there's really two things here and you don't actually need a tune to be able to see these differences so the first one if the filter is actually less restrictive that means the engine doesn't have to work as hard to pull that air into it if the engine doesn't have to work as hard it's going to make more power because it's operating more efficiently the second one is if you can actually bring in more air using a high performance filter if you actually have more air going into the engine the sensors of the engine will see that air going in as a result they will inject more fuel and as a result you will make more power so that's the idea behind high performance air filters so we will get these on the dyno and see if it actually does make a difference now if you're like me and you're buying car parts all the time as we do or whatever else you may be buying this RetailMeNot browser extension which is free is actually a really cool way to save money and it works on all kinds of websites out there so for example I went to Advance Auto Parts comm and put in the specifications of my Crosstrek 2016 with the 2-liter engine and then I went to air filters I found a low cost alternative to the original equipment filter so here's a car quest one for 1699 I put that in my court and as you can see the RetailMeNot extension automatically applies any coupon codes that are out there and it took four dollars and twenty-five cents off the order which is awesome every little bit helps so you can find a link to download the tool in the video description if you're interested and it'll work with all the major browsers out there all right let's get this crush trick on the dyno so first up is our dirty air filter so with each of these filters I'm going to be doing three dyno pulls and then we're going to be comparing the best run of each air filter what is its best possible horsepower we will compare each of them individually so our best run with the dirty air filter we are looking at a hundred fifty eight point three horsepower and 130 7.3 pound-feet now the Subaru Crosstrek from the factory at the crank has 148 horsepower and 145 pound feet of torque so what these numbers are telling us is that this dyno is reading high now I'm not all concerned about what the numbers are individually more so than what is the comparison between them so as I mentioned in previous videos using a dyno to say how much horsepower does your core have isn't all that useful using it as a comparison before and after making a change that's where dinos are actually very useful so we can look at percentage differences and it doesn't matter all that much what the horsepower numbers are as long as the numbers are getting consistent and we're only changing one variable and then seeing what the differences are so as you can see the dyno is reading slightly high with 158 horsepower knowing that the Crosstrek only makes 148 horsepower however each one of these is on the same dyno same settings and so the comparison will still be valid all right so next up is our clean original equipment filter so now we're answering the question does a clean filter help improve horsepower or does a dirty filter cause you to lose horsepower and so Pete numbers we saw with the original clean filter one hundred sixty point one horsepower one thirty seven point four pounds of torque so an increase of about one point eight horsepower and point two County though on average they were nearly identical so while the peak at the very highest point of the engines torque curve and horsepower curves was just slightly higher on average they were actually about equal so not a big difference and the filter isn't super dirty but there are you know a decent number of bugs and you know dirt and stuff in there so I was a bit surprised that on average not really a big difference between these two filters alright next we get to our car quest our premium aftermarket air filter low-cost alternative to the original equipment filter and we actually have a significant increase in horsepower here so one sixty three point three horsepower and one forty point eight pound-feet of torque so we're looking at three point two horsepower versus the clean stock filter and three point four pound-feet versus the clean stock filter and actually the whole curve kind of did push up a little bit so it looks like this low-cost alternative actually does improve horsepower versus the original equipment filter does it filter as well you know that's kind of the question here is this thing just simply not filtering all that much and that's why it's able to have more horsepower I don't know that's not what we're testing into this video we're simply looking at does performance change and with this low cost alternative so far using the dyno it does look like this actually will make more horsepower than the stock filter alright and finally we get to our high performance filter so the KNN and this is actually pretty cool it did do the best of all four filters so 160 4.4 horsepower for its best run 140 2.5 pound-feet of torque so it's up 4.3 horsepower versus the stock clean filter and its up 5.1 pound feet of torque versus the stock clean filter and that again is pretty much across the entire curve that it did better so less resistance less easier for the engine to pull in that air coming in resulting in more power looks like with the KN so one sixty four point four and one forty two point five pound-feet of torque so next we will get into you know some real-world testing and see do these horsepower numbers to these percentage differences that we're seeing actually match up with real-world numbers in acceleration okay so here's how the real-world testing is going to work I'm going to be using this view box to measure position and we're going to be doing acceleration runs in second gear on the same strip of road each filter will get three pulls and I'm going to be leaving it in second gear we're gonna measure in five mile per hour increments from twenty miles per hour all the way up to 60 miles per hour those five mile per hour increments show us kind of at what RPM are we starting to see gains because I can look at the individual increments and so we'll be doing that if it's from about 2000 rpm to about 6500 rpm that we'll be measuring so the two numbers that I'm going to focus on for this video is what was the 20 mile per hour to 60 mile per hour time how long did that take and then what was the 45 mile per hour to 60 mile per hour time and the reason for that lower that higher end there with the 45 to 60 is that will show us if the top end is actually seeing any performance gains like we may have seen on the dyno and so overall is there an improvement and then on the top end is there an improvement okay so first up is the stock filter which is dirty and I ran these runs kind of in a randomized order temperature outside remain the same pretty much the whole time at 53 Fahrenheit but I kind of randomize the order of the testing that way you know we could keep things consistent we didn't have to worry about the fuel level dropping lower and that affecting the way things like that anyways I tried to do this as fair as possible for all of the individual filters and up first we are going to be looking at the numbers for the stock dirty filter which had a 20 mile per hour - 60 mile per hour time of eight point nine six seconds if you thought you should buy a Crosstrek as a drag vehicle you might want to think again these things are wildly slow but from 20 miles per hour to 60 miles per hour with this dirty filter did that in 8.9 6 seconds from 45 miles per hour to 60 miles per hour it did that in 3.5 9 seconds alright so then I popped out the dirty filter stuck in the clean filter measured hour 2260 time and forty-five to sixty mile per hour time and it was nearly identical so 9.01 seconds from twenty to sixty and then three point six one seconds from forty-five to sixty this is about half a percent of a difference and it lines up with what we were seeing on the dyno because on average the torque in the horsepower really weren't very different between these two and then looking at the real-world testing we're seeing the stock filter that's clean actually do about half a percent worse than the dirty filter but you know within a very narrow margin and so basically they're identical clean and dirty didn't make too much of a difference as far as the acceleration dyno results as well as the real-world results kind of showing the same thing okay so here's where things start to get interesting with the CARQUEST premium aftermarket filter so the numbers we saw with this 20 to 60 miles per hour in 8.9 1 seconds at about 1.2 faster than the stock clean air filter and then from 45 miles per hour to 60 miles per hour did that in 3.5 6 seconds so about 1.2 percent faster as well now on the dyno for this car quest versus the stock filter it was about 2% better out in the real world we're seeing numbers about 1.2 percent better so they do you know correlate as far as it looks like on the dyno this did better and then in the real world that also did slightly better now these are just you know air filter changes so it's a minor thing and it's going to be challenging to actually say does it actually improve it by exactly one point two percent but the data does correlate and doing this many different runs using two different methods and having them kind of line up leads me to believe that this does actually provide a small increase in horsepower based on the numbers that I'm seeing and finally the moment of truth does the high performance air filter actually provide any benefit in the real world so it says right on the box designed to increase acceleration and horsepower and so on the dyno we saw an increase in horsepower and in torque of about 2.5 percent to about 3.5 percent and then out in the real world 28 to 60 miles per hour in 8.8 1 seconds our fastest filter tested 45 to 60 miles for our in three point four nine seconds once again the fastest so real-world testing is about two point two five to three point two five percent faster on the dyno we saw about 2.5 to 3.5 percent faster so the numbers actually do correlate real world and on the dyno which is pretty cool to see so overall it looks like yes a performance air filter can actually allow your engine to make a bit more horsepower again the numbers are pretty small here it's not like you're gonna get put back in your seat and thrilled with all the performance that you get but for how easy it is to do and for how little it costs it actually does make a difference which is cool now there is one more point I would like to make because the Crosstrek does have a charcoal filter built within the air box so your air first passes through the air filter and then after passing through the air filter it has an additional restriction this charcoal air filter and so this is here so that when you shut the car off any gases from the evap system do not evacuate out through the intake you don't have any gasoline coming out the intake but this is an additional restriction but it is a permanent piece of the airbox so there is actually plastic tabs if you wanted to remove this you would have to cut them it's not something that's serviceable that you exchange it is an additional restriction though and so the reason why I decided to leave it in for this video is because I think most people if they're simply gonna drop in an air filter they're not going to think about this thing they're gonna pop in whatever air filter they may choose whether it's original equipment whether it's aftermarket or whether it's high performance dropping in and we still did see a difference with them but for a future video I will of course be testing this to see does it actually make a difference if you pull this charcoal filter in and out and will it make a difference with a stock filter versus an aftermarket filter so we'll be testing that out in a future video but something I think worth noting because some vehicles do have these charcoal filters which act as an additional restriction within your intake so in conclusion do high performance air filters actually make any difference can they increase horsepower can they increase acceleration well according to the data in this video yes which is very cool to see and again a huge thank you to RetailMeNot for sponsoring this video I've got a link if you'd like to download that extension for your browser can help save you some money on car parts which is always awesome or whatever it else it may be that you are purchasing thank you all so much for watching if any questions or comments of course feel free to leave those below

Channel: Engineering Explained

Views: 4,273,473

Rating: 4.8822122 out of 5

Keywords: air filter, performance air filter, does it work, horsepower, torque, cars, engineering, science, test, garage, explained, how it works, car filter, diy, car repair, automotive, auto tech, auto diy, chrisfix, doug demuro, donut media, engineering explained, how cars work, dynamometer, dyno testing

Id: GS69owXpGdY

Length: 13min 24sec (804 seconds)

Published: Wed Nov 14 2018