High-compression engines are designed to operate with a higher compression ratio, which is the ratio of the maximum to minimum volume in the combustion chamber. This allows the engine to extract more energy from the fuel, leading to improved efficiency and power output. By compressing the air-fuel mixture more, these engines can produce greater torque and horsepower. However, high-compression engines often require higher-octane fuel, such as premium gasoline, to prevent knocking, which can damage the engine. They are commonly found in performance vehicles and some diesel engines, where efficiency and power are prioritized.