Editing Atkinson cycle (section)

{{Short description|Thermodynamic cycle}}
{{thermodynamics|cTopic=Processes and Cycles}}
The '''Atkinson-cycle engine''' is a type of [[internal combustion engine]] invented by [[James Atkinson (inventor)|James Atkinson]] in 1882. The Atkinson cycle is designed to provide [[Energy conversion efficiency|efficiency]] at the expense of [[power density]]. 

A variation of this approach is used in some modern automobile engines. While originally seen exclusively in [[hybrid electric]] applications such as the earlier-generation [[Toyota Prius]], later hybrids and some non-hybrid vehicles now feature engines with [[variable valve timing]], which can run in the Atkinson cycle as a part-time operating regimen, giving good economy while running in Atkinson cycle, and conventional power density when running as a conventional, [[Otto cycle]] engine.