For every 10 degrees cooler, you gain one percent horsepower. For every one psi increase in boost, you will have three percent more horsepower. If you take these numbers and multiply them over what you can do with an intercooler, you can see why this is an important component of your truck. The higher intake-air temperature of your turbo reduces the efficiency of an engine and that's why an intercooler is important. This specialized heat exchanger, which bears an uncanny resemblance to a radiator, cools the intake air.
Once the hotter air travels from the turbo's compressor to the air-to-air intercooler, it begins cooling the air. From there, the air travels to the intake manifold, where it's distributed to the cylinders. The injectors shoot in the fuel and the mix burns, creating the high-pressure the pistons need. The spent gases leave the cylinder and then drive the turbine side of the turbo, completing the cycle. When no boost is required, a wastegate opens to allow the exhaust gases to bypass the turbo.
Unfortunately, the intercoolers aren’t a cheap fix. You can expect to pay anywhere from $500 to $2,000 for one, but it does come with great benefits. When you're not using the boost, you're running on a smaller engine, which means increased fuel efficiency.