Data generated from this project are collected from a 4-cylinder, 2.5-liter, naturally aspirated, Atkinson Cycle engine with cooled exhaust gas recirculation (cEGR). The engine was tested by the National Center for Advanced Technology (NCAT), part of EPA’s National Vehicle and Fuel Emissions Laboratory (NVFEL) in Ann Arbor, Michigan, using laboratory test equipment and methods to characterize engine controls, fuel consumption, and emissions. Data from this engine are part of a benchmarking and testing project to assess the effectiveness of numerous advanced low emitting and low fuel consuming light-duty vehicles, engines and transmissions. Citation information for this dataset can be found in the EDG's Metadata Reference Information section and Data.gov's References section.