Overview

• Kawasaki told Japan’s Defense Ministry this month it suspects fuel-efficiency inspection data were manipulated on certain submarine diesel engines.
• An outside special investigation committee is examining the case and is expected to deliver a final report within the year.
• Reporting indicates the alleged practice involved rewriting measured values from post-assembly test runs to satisfy required specifications.
• Kawasaki says it is withholding details during the probe and currently believes there is no impact on submarine operations or safety.
• Coverage notes broader context: prior admissions of similar falsification on commercial ship engines in 2024, related misconduct inquiries tied to submarine repairs, and claims under review that the issue could span about two decades and affect multiple active classes.