IHI Power Systems falsified fuel efficiency data for 4,361 engines since 2003.

IHI Corp.'s subsidiary, IHI Power Systems Co., falsified fuel efficiency data for 4,361 engines since 2003, used in ships, trains, and potentially fishing boats. The data manipulation was discovered at plants in Niigata and Gunma prefectures. Among the engines, 2,058 did not meet customer specifications. The misconduct came to light after a whistleblower reported it in February.