What is an Intercooler?

Automotive charge air cooler

Charge air coolers, which some people also refer to as air cooler chargers, or intercoolers, are an important part of the combustion process for engines with turbochargers and superchargers. They cool air after it has been compressed by the turbocharger but before it enters the engine. This results in enhanced efficiency as well as both improved power output and longevity. Let’s dive a little deeper.

What’s The Purpose of a Charge Air Cooler?

Charge air coolers, or intercoolers, cool down air for combustion. But why does the temperature of compressed air from the turbocharger need to be cooled down in the first place? Simply put, doing so provides denser cooler air that helps more air get in the cylinder in total and make the air/fuel charge less prone to the pre-ignition or detonation, so we can run more timing advance and get more power out.

Charge Air Cooler vs Intercooler vs Aftercooler

Charge air coolers and intercoolers are not one and the same, but they’re also not entirely different. Repair shop Kell Radiator Service does a great job of explaining why that is in their blog post “4 Facts About Charge-Air Coolers for Forced Induction Engines”; they explain:

Though charge air coolers are also sometimes referred to as aftercoolers, intercoolers, or turbo coolers, each of these is slightly different.

The term “charge air cooler” and intercooler are often used interchangeably, but technically charge air cooler is an umbrella term for intercoolers and aftercoolers. Where the charge air cooler is placed in the car determines whether it’s technically an intercooler or aftercooler. ;

Aftercoolers in particular cool compressed air after the entire compression cycle, whereas intercoolers cool it specifically before entering the engine.

But realistically speaking, the term “intercooler” has come into common usage as an interchangeable term with “charge air cooler” and the term “aftercooler” has fallen out of favor with most people — even experienced enthusiasts.

Types of Charge Air Coolers

There are two main types of charge air coolers you’ll find available.

  • Air to air cooling systems: Air to air coolers use ambient air to cool the compressed charge.
  • Air to water cooling systems : Air to water coolers use a coolant liquid, and they are almost always used in applications where the vehicle space (packaging) requires it.

Water is a much more efficient conductor of heat than air, so air to water charge coolers can be incredibly effective, but for their intended purpose, air to air coolers also work well.

Radiator vs Charge Air Cooler

“Wait a minute!”, you might be thinking…Doesn’t my engine have a radiator to cool down the engine? Yes. But while charge air coolers lower the temperature of compressed air specifically for the intake system, radiators cool engine coolant for the entire engine. It’s also worth noting that air to water intercoolers in particular, which are a common upgrade for Audi vehicles with existing air to water setups, have a separate radiator often referred to as a “heat exchanger”.

Learn About Your Charge Air Cooler & Intercooler Options

Curious to see how you could improve your VW, Audi, or Porsche’s performance with an intercooler? Shop all our intercooler systems now. We’ve got a wide range of options for you to explore. Whether you drive a VW MK7 or MK8, an Audi B8 A4, or a VW MK5 or MK6 GTI, we’ll get you equipped with the right charge air cooling system for your vehicle.