What Does a Cold-Air Intake Do, and Is It Worth It?

ram-1500-trx-2021-04-air-intake--exterior--front--gray--grille--logo.jpg 2021 Ram 1500 TRX | photo by Mike Hanley

The purpose of a cold-air intake is to find cold air in an otherwise hot under-hood environment. It can do this by drawing air from above the hood, under the front bumper or a spot inside the engine compartment that isn’t as hot as other places.

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Why? More power — maybe. Sometimes called cold-air induction, the theory behind a cold-air intake is sound: Cold air is denser than hot air, so cold air packs more oxygen into a given volume than does hot air. (Note that air only contains about 21% oxygen, with nearly all the rest being rather useless nitrogen.) Since it’s the oxygen in the air that combines with fuel to make the engine run and produce power — and that air-fuel balance is kept at a relatively stable ratio — the more air you can get into the engine, the more power you can get out.

Factory Vs. Aftermarket Options

Some cars come with a factory cold-air intake, and many aftermarket companies sell bolt-on systems. Many of the latter include smooth aluminum or plastic air-routing tubes that are said to improve airflow, while at the intake end carry a large, washable air filter that’s often easier to get to than the stock, disposable paper filter. In some cases, the filter is situated low or off to the side in the engine compartment, and it’s sometimes walled off from engine heat with a shield.

Is It Worth it?

Maybe, but in regard to adding an aftermarket cold-air intake system, there are a lot of variables in the equation.

If your goal is to make a throatier intake sound, gain the benefit of a washable (rather than replaceable) air filter or to add a cool-looking touch under the hood, then yes — the aftermarket cold-air intake system will likely work for you. But as to whether it actually adds any horsepower, well, that’s less of a sure thing.

In terms of adding power, so much depends on the design of the new system and on the design — or condition — of the old one.

Ads for aftermarket cold-air intake systems often include ambiguous “up-to” horsepower claims, which are always red flags. Yet in truth, that’s fair; the aftermarket manufacturer has to cover all possibilities, and the type or condition of your current system is an unknown. But as a stand-alone add-on, a cold-air intake system is probably not going to show much, if any, of a performance improvement. If, however, you’re also adding other modifications such as a low-restriction exhaust system, an effective cold-air intake might do more good.

One thing that’s important to keep in mind has to do with how precise and finicky modern engines have become. Changing one part or system — even if it may seem to be an improvement — might adversely affect another, which could bring on the dreaded check-engine light.

Thus the benefits and risks of adding an aftermarket cold-air intake system may not be known until after you’ve spent the money to buy it and the time (or money) to install it. So whether it’s worth it to you may depend on how much you’re willing to gamble.

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