What is the role of an intercooler in an engine with a turbocharger?

• A. Cools compressed air to increase density, improving power and reducing intake air temperature.
• B. Heats compressed air to improve combustion efficiency.
• C. Increases turbocharger speed by recirculating air.
• D. Filters intake air to remove particulates.

Answer: (A)

Intercoolers cool the air after it’s been compressed by the turbocharger. Compression heats the air, but cooler air is denser, meaning more oxygen enters each cylinder. This lets the engine burn more fuel more efficiently, producing more power. Cooling also helps prevent knock by lowering the intake temperature, allowing the turbo to run with more boost without harming the engine. The intercooler works like a radiator for the intake charge, using ambient air or coolant to remove heat before the air reaches the cylinders. The other ideas would either heat the air, which reduces density and power; or involve changing turbo speed or filtering air, which aren’t the intercooler’s functions.