In a turbocharged engine, which component primarily increases the pressure and density of intake air?

• A. Radiator
• B. Turbocharger
• C. Intercooler
• D. Water pump

Answer: (B)

Boost in a turbocharged engine comes from compressing the intake air to raise its pressure and density. The device that does this is the turbocharger, which uses exhaust gas to drive a turbine connected to a compressor. That compression pushes more air (and thus more oxygen) into the cylinders, boosting power. After compression, air is hot, and its density drops, so an intercooler is often used to cool the air and increase density further, but it’s the turbocharger that primarily increases pressure. The radiator and water pump are part of the cooling system and don’t affect intake air pressure.