What is the primary benefit of having a higher compression ratio in an engine?

A higher compression ratio in an engine leads to improved thermal efficiency, which is the primary benefit of such a design. When the air-fuel mixture is compressed more before ignition, it allows for a more complete combustion process. This means that more energy from the fuel can be converted into useful work, increasing the engine's efficiency.

Higher thermal efficiency also means that for a given amount of fuel consumed, the engine can generate more power and with better performance. This is due to the fact that the increase in temperature and pressure during combustion allows the engine to extract more work from the fuel. Therefore, an engine with a higher compression ratio can often operate effectively on higher-octane fuel, which can further enhance performance and efficiency without leading to knocking or pre-ignition.

In contrast, a higher compression ratio does not necessarily correlate with increased fuel consumption, more exhaust emissions, or decreased engine power, which are characteristics associated primarily with inefficient combustion or design flaws. Instead, it focuses on maximizing the energy extracted from the fuel through more efficient combustion processes.