As technology has advanced, more vehicles are being built with high-tech features that increase efficiency, safety, and comfort. One of those features includes cold air intake systems. When this air is drawn in, a higher amount of fuel can be consumed by the engine. The engine operates at a higher RPM and produces more horsepower. This, in turn, leads to more speed for the driver. But, what about the cold air intake in the engine? Does it increase MPG or fuel economy? Let’s find it and discuss it with some facts.
Are you also thinking to switch to bigger tires? Read my guide on how big tires affect MPG.
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Does A Cold Air Intake Increase Mpg?
Cold air intake systems can increase MPG and improve fuel economy by only a few percent. This is because a cold intake air system allows your engine to breathe more freely and keeps the incoming air cool by taking the air away from the heat of the engine. Cool air is dense and carries more oxygen with it. The more oxygen is in the air, the more power is consumed due to efficient combustion. As a result, fuel burns more evenly and the engine will produce more power with less fuel consumption.
However, engineers have already designed an air intake system by installing the inlet of the air filter closer to the car fender instead of keeping it in the engine bay. So, in that case, the cold air intake system won’t show any noticeable effect on MPG. In those engines, you can save your cost by installing only drop-in filters instead of cold air intake systems to enjoy a deep sound of airflow and notice some improvements in horsepower.
How Does Cold Air Intake System Work?
Cold air intake system works by providing a less restrictive path to the intake air by passing it through a straight metal pipe and a conical air filter. A cold air intake system does not have any restrictions like a resonator.
In cold air intake systems, heat shields are incorporated to protect the intake air from the heat of surrounding engine components that are hot enough to increase the temperature of the intake air.
However, some cold air intake systems are less restrictive, but they still draw air in front of the hot engine bay and behind the radiator. In that case, a cold air intake isn’t worth anything as it will not perform its job efficiently. If the aftermarket intake system is just a pod filter with a short length of piping under the hood, it is not going to make much difference as the filter will be still located in the hot engine bay.
The pod filter is a cone-shaped high-flow air filter in aftermarket air intake systems is designed to suck more air and produce more horsepower. Moreover, due to a conical design, aftermarket air intake systems produce a louder sound during acceleration just like straight pipe exhaust systems.
When installing cold air intake, you should tune the ECU if the aftermarket intake system has a larger inlet pipe. In that case, you would need a bigger throttle body, and the MAF (Mass Airflow) sensor isn’t going to be mapped to the high flow of air.
The largest potential downside of cold air intake systems is water inhalation. Your factory intake is very good at protecting the car from getting a big slug of liquid. Even with shielding, your chance of sucking up water and damaging your engine is significantly higher with a cold air intake system.
Efficiency of Cold Air Intake Depends On Vehicle
In some vehicles, factory airboxes are next to perfect and do not offer any restrictions on the upcoming air. In modern vehicles, factory air intake is a cold air intake, pulling air through the grille, fender well, or something along those lines.
Aftermarket so-called “cold air” intake systems are not worth it because they put an exposed filter with no separation in a hot engine bay.
For example, in the below picture, you can see that an aftermarket K&N cold air intake filter is exposed to the engine bay. Although it is withdrawing air from the fender well, the cone-shaped air filter is exposed to the hot engine bay.
Here is what a user says about the stock air intake system in his vehicle:
“There’s a duct that goes from the air cleaner snout to the grill, pulling in cooler air than what’s available under the hood.”
If you see the initial 5 minutes of the youtube video below, the stock air intake system is also drawing air from the fender well without exposing it to the engine bay.
Using Drop-in Filters
Drop-in air filters are designed to flow more air than your OEM air filter, but they don’t have any cons that are associated with aftermarket cold air intake systems. People have observed a 1-2% increase in HP by using aftermarket drop-in filters. You can easily install them in the OEM air filter box.
Most car owners, instead of getting a $400 aftermarket cold air intake system, only replace the OEM air filter with a high-performance K&N drop-in filter in the vehicles with factory-installed cold air intake systems. Those filters will only cost you around $60.
Note Your Driving Style While Installing Cold Air Intake
Your driving style also greatly impacts MPG after installing the cold air intake system. A true cold air intake system only improves power and fuel economy at higher RPMs.
If you’re a daily driver, you will spend way more time at low RPM than at high RPM, so it can be a detriment to use a cold air intake system. If it’s a track toy or you drive like a maniac all the time, the high RPM benefit of a cold air intake system can be worthwhile.
So, you will not face much difference in MPG and fuel economy with a cold air intake system until the engine revs above 4,000 RPM. This is because airflow requirements increase with RPM. The engine throttles more as the accelerator pedal is depressed. So, to reap the benefit of cool, denser air with a high flow through a cold air intake system and find a noticeable difference in fuel mileage and horsepower of your engine, you need to rev at high speeds.
Apart from this, if your vehicle remains mostly in low to mid-range RPMs, you can significantly improve the MPG by just improving your driving style.
The easiest way to noticeably improve the fuel economy of your engine is with your foot. You should moderately press the accelerator. If you accelerate heavily from a stop, it will consume more gas until you get to your normal cruising speed.
Similarly, aggressive braking also damages the fuel economy or MPG as the significant energy generated by the fuel is converted to heat due to excessive friction between brake pads and the rotor. So, avoid accelerating rapidly to overcome other cars or immediate breaking not to hit the next one.
So, does cold air intake increase MPG? I would say that reducing airflow restrictions and air temperature with a well-designed and properly located Cold Air Intake can enhance performance and MPG. The results after installing cold air intake entirely depend on the condition of your OEM air filter and the installation of a stock air intake system.
The point of the CAI is to draw cold air from outside of the engine bay. If the air is exposed to a hot engine bay, there isn’t any significant benefit of spending $400 on a cold air intake system to achieve a few percentage of improvements in the MPG.
If you ask my opinion, I like Spectre and Volant CAI. In Volant CAI, the filter is fully enclosed in a box. Volant CAI also comes with a Scoop that runs down closer to the ground that sucks air in from the grill, thus taking the much cooler.
You can buy any of those cold air intake kits and test the air intake temperatures and MPG after the kit is installed. Amazon has a refund policy. So, that won’t be an issue. furthermore, replacing stock exhaust and headers with the aftermarket exhaust system, having a wider piping and less restrictive muffler. In most cases, you’ll lose some low-end torque but as you climb higher in RPMs you will be utilizing the higher flow and making more power.