The difference between turbocharging and supercharging:

The structure and working principle of the turbocharging system will not be discussed. This system directly uses exhaust gas energy, not only does not consume additional power, but also performs positive pumping work on the piston under most working conditions; After supercharging, the power output, fuel economy and emissions under medium and high operating conditions can be greatly improved while maintaining the engine performance under low operating conditions; In addition, the volume, weight, cost and reliability of the supercharger are decreasing, which makes this supercharging method more and more widely used in vehicle engines.

The compressor of the supercharging system is directly driven by the engine crankshaft through the transmission device. Because the dynamic response of the mechanical transmission is faster than that of the exhaust, it does not interfere with the exhaust system, which is its advantage. In addition, unlike the turbine lag in turbocharging (the turbocharging will not start at low speed), the effect of supercharging is less affected by the speed, and similar supercharging effect can be achieved at all speed conditions. Therefore, supercharging is particularly suitable for improving the power output of the engine at low speed, so it is widely used in racing engines and passenger car engines pursuing low-speed acceleration capability.

Most low-end cars in Europe are diesel engines. For diesel engines, turbocharging is inherently more suitable for diesel engines than supercharging because of its small speed range and high exhaust pressure. In order to cope with the increasingly stringent emission regulations, European manufacturers have chosen the path of reducing emissions and adopting turbocharging, which has led to the more widespread situation of turbocharging today.