Turbocharging systems are mainly divided into four basic types: mechanical supercharging, exhaust gas turbocharging, wave supercharging, and compound supercharging. Mechanical supercharging drives the supercharger via the engine crankshaft, delivering quick response but consuming part of the power, and is commonly found in 3.0T engines of models like the Audi A6L. Exhaust gas turbocharging uses exhaust energy to drive the turbine, enhancing fuel economy with a significant power boost; for instance, the small-inertia turbine used in the Corolla 1.2T can mitigate lag. Wave supercharging relies on exhaust pulse waves to compress air; while it boasts high supercharging efficiency, it is bulky and mostly applied in diesel engineering vehicles. Compound supercharging combines the advantages of mechanical and exhaust gas turbocharging, balancing low-speed torque and high-speed power, but features a complex structure and high maintenance costs, with the Porsche 911 as a typical representative. Additionally, there are derivative technologies such as single-turbo dual-scroll (BMW 5 Series) and variable geometry turbo (Porsche 911), which further improve performance by optimizing airflow control. Currently, mainstream models generally adopt exhaust gas turbocharging solutions, while high-performance models tend to use twin-turbo or compound systems to achieve broader power coverage.
