Is that performance air filter actually helping your car?


The automotive aftermarket is flush with products promising to improve the performance of your car. Since swapping air filters is easy enough for any do-it-yourselfer, there are dozens of aftermarket air filters out there that claim you’ll see big improvements. But do they really work? YouTube’s Engineering Explained decided to put them to the test.

This is a companion discussion topic for the original entry at https://www.hagerty.com/articles-videos/articles/2018/11/16/do-performance-air-filters-actual-work


It IS interesting.
But wait…he didn’t test the oil-bath filter I’m still running in my old Chevy! Got to be worth 10 hp…at the wheels! :wink:


@Jim-R PLUS you get the benefit of the “factory installed chassis self-lubrication system” keeping the floor pans and the suspension components well lubricated & rust free. (Commonly known as an “oil leak” by the uneducated heathens…). The benefits aren’t quite as noticeable on the 0-60 acceleration charts, but they do pay off over a lifetime of car ownership.


But was there any appreciable difference in performance at anything other than wide open throttle? My thought is that the performance filter would only make a difference when the airflow was maxed out on the regular filters.


You forgot the logical last part of the comparo: no filter at all. The “best” numbers will result of course with no filter in the air box; it would be the least restrictive. But there’s an important reason you run with a filter. So, sure, you can gain a couple of horses, but more “dirt” will flow into the intake when you do. You cannot have one w/o the other. BTW: “designed to increase performance” is NOT the same as saying “does increase performance.” Weasel marketing lingo.


So, now we need to know about particle removal performance… does that K&N let all kinds of diamond hard and sharp mineral (dirt) particles in to chew away at the precise tolerance mating surfaces of your precious engine?


Here’s a great review that’s actually based in science:


@greg2 … ^Great article with good points…saved. The other potential issue that may have missed mention with ‘wet’ filters such as K & N is when the user over-oils the media and it fouls the MAF sensor. Not a big deal, easily cleaned but…
That said, I think there is a place for high-flow filters, at least in forced induction cars. I use one but that car is a twin turbo with a MAP system…so high volumn need and no exposed sensor.
Plus many aftermarket manufacturers utilize one of the ‘custom’ filter configurations offered by K & N which allows things like larger intercoolers to be installed.


i put a K N filter in my 67 Camaro not only does it sound great when i punch it but looks good and i might received a bit more HP


I was a big fan of those K&N oiled filters till I read a piece about the oil used to recharge the filter element can and does find its way on to some sensors along the way to the throttle plate and then into the upper plenum…it effects the signals sent by the air charge temp sensor and the idle air control motor on most computer controlled engines…I believe we have been using pleated panel air filters now since the first round of OBD…way back in the early 70’s… I know if they say "its better " and have some race team swearing by them then I guess we fell for it…most race cars ( on or off road ) have no emission controls on them …dirt racer love them because they can be cleaned and reused but if you think the normal use of a everyday driver need a 60 dollar filter you have to recharge every 3,000 miles then you not and everyday driver…I went back to OEM style air filters because they are what the engine was designed to use…12 months /12,000 miles at 9 dollars a piece seems really cost effective and simpler for my 3 cars…there are some really top rated air filter out there now that boast less restrictive air flow for better response and more horse power…but as I see it…not one major auto manufacture has any oil soaked filters on its current high horse powered super cars…they may have high flow cone styled ones but I bet they aren’t recharge types…to each their own I keep hearing about this topic… it about 20 degrees here in Chicago and I still have about 5 months till I need to check/ change my daily drivers air filter…Our 89 Mustang will sit till May and the new suv has only 7500 miles on it… so I will not need to look at any air filter till it gets warmer here…