Editing Reciprocating engine (section)

==Power==
Reciprocating engines can be characterized by their [[power density|specific power]], which is typically given in kilowatts per litre of [[engine displacement]] (in the U.S. also [[horsepower]] per cubic inch). The result offers an approximation of the peak power output of an engine. This is not to be confused with [[fuel efficiency]], since high efficiency often requires a lean fuel-air ratio, and thus lower power density. A modern high-performance car engine makes in excess of {{cvt|75|kW/L|hp/in3|sigfig=3}}.