Several synonyms can be used to describe the concept of power per liter of displacement, a key performance indicator within the automotive industry. One alternative term is engine power density, which refers to the relationship between the power generated within an engine and its size or displacement. Another term is specific power, which measures the output power per unit of weight or volume of an engine. Additionally, horsepower density, engine capacity ratio, and displacement efficiency can all be used to describe the power generated by an engine relative to its size or displacement. These synonyms are commonly used to compare the performance of different engines and to evaluate the efficiency of automotive powertrains.