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K&N Drop in Filter vs Cold Air Intake

K&N Drop in Filter vs Cold Air Intake

Drop in filters and cold air intakes are popular aftermarket modifications designed to improve the performance of your vehicle.

The right application will help your ride breathe better while adding horsepower.

What I like about both methods of increasing the performance of your engine is how relatively inexpensive they can be.

The second thing I like about them is that installation doesn’t require much mechanical know how – This was the first performance mod my brother made to his car when he was in high school.

Come, let’s take a closer look at what you can expect with a K&N drop in filter vs cold air intake.

Drop in Filters

Choosing between a drop in filter and a full-on cold air intake system depends on your performance goals and budget.

As a high school student and short on funds, my brother first went with the more economical route of simply dropping in an air filter into his 1994 Honda Civic DX coupe.

Novices to the world of engine performance sometimes confuse a simple drop in filter with the more elaborate cold air intake system. I sure did.

But my brother corrected me showing me that while an aftermarket air filter does a great job of allowing more air to flow into the engine more freely than factory air filters even adding more power.

None of those gains compare to what you get with a cold air intake system.

That’s why whereas you can easily pickup a drop in filter for something like thirty bucks, splashing out for cold air intake will set you back around three hundred dollars.

Cold Air Intake

But with a goal to serious improve the performance of his car, my brother of course quickly graduated to a cold air intake system.

Not only did it increase horsepower numbers, but it gave the car a deeper more aggressive growl that put a smile on both our faces.

Cold air intakes are designed to increase engine performance by drawing in cold air into the engine.

The system consists of an intake pipe and a filter that’s usually in the shape of a cone.

This filter is usually placed anywhere it can draw in cool, fresh air from outside the engine bay.  

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Not only can both respiratory improvements help the engine breath more deeply, translating into gains of up to 30 HP.

But since more oxygen helps the engine burn fuel more efficiently, fuel economy is also improved.

The Difference a K&N Drop-In Filter Makes

A stock airbox is engineered to do a good job of directing cool air into the engine and keeping hot air out of the intake.

But a K&N drop-in filter does a better job – that’s why it costs more.

A K&N filter has multiple layers of fibers all working to hold back particles from entering your engine.

Paper filters don’t have that many filters and get clogged more quickly, which is why you have to change them more often.

Not only that, but a K&N filter is designed to drop right into the stock air box for a perfect fit.

Along with more airflow, your engine gets a marginal horsepower and torque increase. It’s a performance increase your sure to feel in immediate throttle response.

Of the two options, this is the cheapest way to get some horsepower gains.

K&N Drop-In Filter Horsepower Numbers

I use K&N filters.

Yeah, they’re a little more expensive than the regular paper filters and maybe I’m being biased. But the cars I’ve installed them on seem to perform better with K&N’s filters.

Horsepower gains are modest, though. You should expect something like a gain of 5 to 10 horsepower which your butt dyno isn’t really going to feel.

But I’m a firm believer in that if you take care of your machine, it’ll take care of you.

You don’t have to take my word for it. Road and Track conducted a test pitting a high-performance filter by K&N against a cheap, non-performance air filter by CarQuest, a new OEM filter and an old OEM filter.

The result?

The aftermarket filters made more power than the OEM one with the most gains coming from the K&N filter.

Cons of Adding a K&N Drop-In Filter

K&N filters come highly recommended because of their ability to keep junk out of your engine, and because of the proven performance gains.

But like any product in the world, there are some drawbacks worth considering before pulling the trigger:

  • The problem with using drop-in filters like K&N is that they use an oiled filtering element. This can cause long term problems if you’re installing one on a vehicle with a mass air flow sensor.
  • As oil builds up over time it can cause sensor errors which require cleaning to correct. This happened to me on a Nissan Maxima I owned.
  • And speaking of oil, you have to re-oil K&N filters if you want to reuse them which can cost about $20 at the high end. But the kit will last for several uses.
  • Plus, not all K&N filters are made the same. Using a low-quality K&N filter exposes your engine to debris and contamination.
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Cold Air Intake is Better Than Just a Filter

Don’t get the wrong idea. When it comes to a K&N drop in filter vs cold air intake, it’s not so much that one is better than the other.

Both parts work together to help your vehicle perform better. A performance cold air intake replaces the stock intake with a wider tube with fewer bends.

Fewer bends gives oxygen more unrestricted passage to the engine for better combustion. Translation: more power.

The cold air intake system also relocates the air box outside of the engine combustion area so that cooler air can be sucked in through the air filter.

There are plenty of options when it comes to selecting the best cold air intake.

The right choice for your vehicle comes down to where you drive as much as your driving style and budget.

Horsepower Numbers with Cold Air Intake

Here too, the horsepower gains aren’t massive.

But with the air intake moved further away from the engine allowing cooler air to get sucked into the combustion chamber.

You should expect around a 5 to 20 horsepower increase.

How does this happen?

Cold air is more dense than hot air resulting from the increased number of oxygen molecules.

All these tightly packed oxygen molecules sent into the engine through the intake system creates a larger combustion which creates more power.

Not just more power, but since fuel is burned more efficiently. It also increases fuel economy.

And with fuel prices the way they are, even if you’re not looking for increased horsepower numbers that simple fact alone makes a cold air intake totally worth it.

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Cons of Adding a Cold Air Intake

Yes, a cold air intake does allow your engine to receive a denser concentration of oxygen leading to better performance and fuel economy.

But because you need to find a way to route the tube from the engine’s intake to a source of cold air, it makes these systems more expensive than just dropping in a K&N filter.

The added complexity also makes a cold air intake more challenging to install than just a drop-in filter.

Not only that, but this colder location often exposes the air filter to more debris and moisture than the factory setup.

Placement is crucial to the success of a cold air intake. If it’s raining and the filter is placed in a location that exposes your engine to ingesting a significant amount of water, your engine will hydrolock.

Which means you’ll need a new engine. It happened to AutoVlog.

Other Ways to Add 50 HP to Your Car

So, after considering the pros and cons of a K&N drop in filter vs cold air intake, what are you thinking?

There are other means by which to increase your vehicle’s horsepower and torque.

I’ve found a simple tune up to be effective if the performance of my car seems to be lagging.

While this option won’t necessarily add horsepower it will free up your car’s performance.

After the cold air intake, the next thing my brother did was install an aftermarket exhaust system.

Stock exhaust systems tend to come with a lot of materials that restrict power as well as noise.

You can also reprogram the ECU to unlock more power from your vehicle for around the same cost as a cold air intake system.