NIIGATA—The transport ministry is conducting on-site inspections of two plants of an IHI Corp. subsidiary that have falsified fuel economy data for ship and railway engines for at least 20 years.

The revelation follows similar disclosures from an IHI Corp. subsidiary and Hitachi Zosen Corp. earlier this year. The affected engines were used in midsize and large commercial vessels that ...

IHI Corporation with 0.018%, Safran S.A. with 0.01485%, MTU Aero Engines AG with 0.01477%, Mitsubishi Heavy Industries Aero Engines Ltd. with 0.013% and AECC Commercial Aircraft Engine Co. Ltd ...