The turbocharger compresses the intake air, causing its temperature to rise. Under high engine loads, high ambient temperatures, or prolonged operation, the intake air may heat up further. A high-performance charge-air cooler removes this heat before the air enters the engine.

Under normal use, the stock intercooler may be sufficient. However, if you frequently drive under high load, in hot conditions, on sand, or make repeated hard accelerations, a larger version may be worthwhile to keep intake air temperatures under better control.

High intake air temperatures can increase thermal stress and worsen the conditions for optimal combustion. The engine management system may also limit power to protect the engine. Improved charge-air cooling helps control the intake temperature under heavy loads.

Not automatically. A larger intercooler is primarily a cooling measure, not a standalone performance upgrade. Its benefit is lowering the intake air temperature and helping maintain more consistent performance under heavy load. Improved intercooling can be particularly relevant in a turbo system with increased power.

The engine radiator lowers the temperature of the engine coolant, while the intercooler cools the intake air compressed by the turbocharger. Both systems serve different purposes and contribute to the vehicle’s thermal management.