Do Cold Air Intakes Make A Difference ?

Over the past 10-15 years, I have had a LOT of people ask me “ Do cold air intakes make a difference ”.

If it’s not that exact question, its something like “ Does a cold air intake improve gas mileage ” , or “ Does a cold air intake increase HP ”?

Cold air intakes are probably one of the biggest debated items I hear around in car circles from people who haven’t had a lot of experience with automobile performance modifications.

There are a Lot of people who LOVE their cold air intakes and say it was the best ‘first modification’ they did to their vehicle.  There are others who say “Well, if the automakers thought this was a better design, they would have designed it like this already”.

In this article, I am going to explain what an air intake is, the flaws of the factory air intake designs, the benefits of adding an aftermarket cold air intake, and the various designs of aftermarket cold air intakes available on the market today.

If you want to find out the answer to the question “ Do cold air intake make a difference ?“ , keep reading and I will explain every last detail about these products.

 

How does a cold air intake work ?

First of all, let’s start with the basics.  What does an air intake do?

The purpose of the air intake in any automobile is to supply the engine with the air that it needs to use, along with fuel, to maximize the efficiency of the explosion that takes place within the combustion chamber.

 

Engine diagram - combustion process

 

***The picture above shows the locations of the intake air, fuel, spark plug, exhaust air, combustion chamber, piston, and crankshaft.

This explosion that occurs when the fuel and air mixture is ignited by the spark plug, creates power that forces the piston down to make the crankshaft turn.  The power from the rotation of the crankshaft is passed through the transmission to the driveshaft(s), and then on to the wheels.

NOTE: In a diesel engine, there are no spark plugs.  The combustion is achieved by a combination of pressure & temperature to ignite the fuel in the chamber.

For any engine to complete this combustion process to maximum efficiency, it must be able to get the correct amount of fuel and air needed to respond to the drivers demand (how much pressure on the throttle/gas pedal).

Additionally, if the air being fed into the intake manifold is cooler, the engine can then burn fuel more efficiently which leads to increased fuel economy and some additional horsepower.

 

Where is the air intake on a car

Every car and truck has a slightly different style of factory air intake system.

The easiest way to find it would be by finding where the air filter is located in the engine compartment.

The air filter is usually located in between where the car’s (or truck’s) air intake opening is, and where the pipe carrying the fresh intake air connects to the intake manifold.  If you do not know where your air filter is, it can usually be found in a black plastic ‘box’ or ‘cone’ that has some kind of clamps keeping the filter tightly sealed inside the box/cone.

***The pictures below are ‘typical locations’ of factory air boxes for some modern day automobiles.

Toyota factory airbox locationAudi factory airbox location

 

***The pictures below are the flat style of air filters that a LOT of modern day cars have.

Stock air filter - newer carAir filter - modern cars

If you have an older car/truck that was made in the 1980’s or earlier, you may have a circular metal air filter housing that is mounted on top of the carburetor or throttle body unit.   Check out the pictures below to see examples of these types of filter housings.

Ford V8 Engine Air CleanerChevy 350 V8 Engine Air Cleaner

These circular air cleaner assemblies above will have an air filter that looks similar to the picture below.

Factory Circular Air Cleaner

 

Why are cold air intakes so much better than the factory air intake systems 

Factory intakes are designed for an abundantly wide spread group of customers.

The air intake design is the same for a driver of a pickup truck in Arizona, as it is for another owner of the same make & model of truck in Minnesota or Colorado.  They are also designed simple to cut back on manufacturing costs, and to reduce induction noise for as quiet a ride as possible.

One big issue with most factory air intake designs is that they end up pulling in hot air from the engine bay, which reduces engine efficiency (increases fuel consumption and reduces power output of the engine).  The warm air is much less dense then the cooler air outside of the engine bay is, which means way less oxygen molecules available for the combustion process.

Some factory air intakes even have baffles and/or reduction in pipe size (intake air pipe) to keep the intake as quiet as possible.  These types of designs prevent the air intake from doing their job efficiently.

Factory intake systems, along with the factory designed exhaust systems, are two areas on automobiles that are designed for comfort, noise reduction, and to fit into tight spaces (this is especially true with factory exhaust systems).

Here is a GREAT video made by the people at K&N explaining why their cold air intake systems are far superior to the factory air intake ones.  They also explain their fantastic warranty and their 100% GUARANTEE that their cold air intake systems will increase engine horsepower, torque, and improve fuel efficiency!

 

If you are eager to check out the various brands of Cold Air Intakes available for your automobile, you can do so on the Amazon website.

 

Does a cold air intake increase HP

Aftermarket cold air intakes have been around for many years now, designed to help maximize the efficiency of the air intake system for all cars, trucks, and SUV’s.

These aftermarket cold air intakes help increase fuel efficiency, and overall engine power with their simple designs that are focused on one thing only – to help get the maximum amount of cool air into the intake as possible.

On the performance side, a simple upgrade to a cold air intake will result in a power gain of anywhere from 5 to 15 horsepower, depending on the vehicle and manufactured design.  This is simply from improving the quality and quantity of air flow into the air intakes – cooler air, and lots more of it!

There are several reasons why these aftermarket cold air intakes increase HP (horsepower):

  • The aftermarket filter is made out of a material that allows for high flow of cool air through it and into the intake
  • The filter is also located in an area away from the engine, usually at the front of the engine bay (behind the grill in a lot of cases) allowing for cooler air to enter the intake pipe
  • Heat Shield – most cold air intake systems include a heat shield – to help keep any nearby engine heat away from the filter
  • Less Restrictive Intake Pipe – the piping that goes from the filter back to the factory intake manifold is larger than the factory design, and has a much less restrictive design. These two features help MORE COOL AIR to make its way through to the intake manifold faster to accommodate the engines power needs

By increasing the rate of flow, and the efficiency of air flow into the intake, these cold air intakes are a great aftermarket option.  With proven results from countless tests, air flow studies, engineering, and real world driving, these cold air intakes help your engine optimize its horsepower potential.

If you don’t believe the tests and results from manufacturers and others who have used cold air intakes on their performance cars for years.  Go down to your local drag strip and ask if more, cooler air helps increase the engine’s power.

Still not convinced?  Let’s try to let science prove the point in regards to the relative air density of warm air vs cool air.

Go get a balloon, and then inflate it approximately ¼ full of air while inside your home in one of the cooler rooms of the house.  It doesn’t have to be exactly ¼ , it is for reference only, so just partially fill it up.

Now, tie the knot to seal in the air, and then go outside on a hot day and watch the balloon expand.  Im guessing that it expanded maybe 5-10%? This proves the following point – when air warms up, the molecules get farther apart (the air becomes less dense).  We know that more dense, cooler air is beneficial for maximizing an engine’s performance and efficiency.

Heck! That’s why people love Nitrous Oxide systems for cars….but that’s a story for another day.

If you take that same balloon outside on a hot day in summer in Arizona, that same balloon will expand even more.  What is the point of all the balloon talk?

The air that your engine sucks into the intake via a factory air intake system, is hot air from the engine bay.  Hot air has a LOT less oxygen molecules per CFM (cubic feet per minute) than cool air does.

The increased cooler air provides a TON more oxygen molecules for the combustion chamber to explode with and create more power, while burning the fuel more efficiently.

 

What does a cold air intake do to gas mileage

Ok, so we know that these cold air intakes increase HP (horsepower), but what does a cold air intake do to gas mileage?

Let’s start by going back to the factory designed intake systems.

When Toyota, Honda, Ford, General Motors, etc. design the air intake systems for their automobiles, their primary focus is to design something that operates quietly, is cost efficient, and fits in the crammed confines of whatever little engine bay space is available.

Their engineers for these automakers actually do quite a good job at accomplishing this – we can give them credit for that. However, the designs are simply too restrictive if you are looking top optimize engine power (horsepower) and fuel efficiency.

Basically, it comes down to science when you think about it.

Think about what an engine does – it sucks in air, mixes it with fuel in the combustion chamber to create the power to the crankshaft, and then spits out air (exhaust) after the combustion process.  The engine does this over and over again – that’s how an engine works folks!!  Well, there’s a little more than that, of course, but for now we are just examining how the engine uses air (more specifically – oxygen).

Now, basic chemistry tells is that an automobile engine requires about 14 times more air, as it does fuel, when comparing unit mass of gasoline vs a unit mass of air.

Taking these stats into account, you can see how important airflow is for an engine to operate.

Let’s take a 5.0 litre V8 gasoline automotive engine for instance.  This motor would require about 500 cubic feet of air per minute , at wide open throttle.  To put that number into perspective, consider that a human being’s lung capacity is about 0.2 cubic feet.  If you can imagine trying to take 40 deep breaths in about one second, you can understand how much air these engines require under heavy load.

 

Human lung capacity vs engine air intake capacity

***Above is a great infograph that shows the comparison of the maximum air intake between a human’s lungs and an 8 cylinder automobile engine.  I can’t take credit for creating this one – I found this over on the blog at streetsideauto.com 

 

Considering the information above, you can understand how important air flow (and intake air temperature) is for any combustion motor.  Getting more, cooler air, into the intake helps optimize the engines efficiency.

This means that you will use less gasoline to get from point ‘A’ to point ‘B’ due to the new improved rate and temperature of air being used during the combustion process.

 

So, Do Cold Air Intakes Make a Difference ?

In the article above, we have discussed in detail the benefits of an aftermarket cold air intake system for your automobile.

We have covered the following topics:

  • How does a cold air intake work
  • Where is the air intake on a car
  • Why are cold air intakes so much better than the factory air intake systems
  • Does a cold air intake increase HP, and
  • What does a cold air intake do to gas mileage

We discussed how the increase in cooler air (provided by a cold air intake system) helps the engine run more fuel efficiently.

Does a cold air intake increase HP ? – You bet.  Cooler intake air is ALWAYS better when talking about adding horsepower.  Just talk to the guys at your local track – it’s pure, proven science.

These cold air intakes not only increase HP, and improve gas mileage, but they save you money down the road by not having to replace the air filter over and over again.

That’s right, these aftermarket cold air intakes come with a filter that can be cleaned, and then re-installed for use again, over and over.  Think of how much the replacement factory air filter costs.  I’m guessing anywhere from $15 to $50 on most modern fuel injected vehicles?

For the average driver, the factory air filters need to be changed anywhere from 2 to 5 times a year, and sometimes more.  Of course, this depends on the amount of miles driven and where the automobile is being driven (dusty gravel roads?  Windy desert terrain? – these climates will require a more frequent air filter change).

NOTE:   There is one very important thing to consider when considering the purchase of a cold air intake system.

For those who enjoy the quiet ride of your Cadillac or Lexus, this may not be the upgrade for you.

From my experience over the past 15 years, every aftermarket cold air intake I have seen on a car/truck/SUV increases the sound of the intake air as it’s being sucked into the engine.  For most auto enthusiasts, it isn’t an issue because a lot of us like the slightly more aggressive sound.

However, some people really enjoy the tranquility and comfort of their luxury cars and SUVs – so for these folks, I would NOT recommend such a product.

Just to be clear, I am not ‘mocking’ those who prefer a nice quiet luxury automobile…….my father LOVES his Cadillac Escalade and I totally respect those who share those vehicle preferences.

However, in my opinion, the small increase in noise from the intake air is a minimal drawback (if you aren’t keen on the sound of it) when considering the added engine power and increased fuel economy that these aftermarket cold air intakes create.


 

 

 

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