What happened?
Hino Motors disclosed engine-certification misconduct in March 2022. The Special Investigation Committee later found long-running irregularities involving emissions durability testing and fuel-economy measurements. It also found that, when Japan’s transport ministry asked Hino in 2016 whether any improper cases existed in certification testing, the company falsely responded that there were none.
The investigation report published in August 2022 runs 299 pages. It records not only measurement manipulation but also how development targets were handled, exchanges between executives and engineers, and unusually revealing workplace terms from employee interviews and surveys. The English text below is a From Reports translation and summary of the Japanese original.
Background overview: Hino Motors (Wikipedia)
Eight passages that stood out
The report is unusually detailed about the language surrounding the misconduct: an email sent while a target was still out of reach, what engineers heard when they said a technology was difficult, and what employees called meetings where problem owners had to explain themselves publicly. These eight notes stay tied to the original Japanese pages.
There was no concrete fix for the shortfall. An email still said a +3% data set would be sent for the time being
In December 2005, fuel-economy calculations for E13C-powered vehicles with a 12-speed transmission remained several percent short of the fiscal 2015 target, even after an error in the calculation method was corrected.
The committee inferred that, despite having no concrete countermeasure to close the shortfall, the employee was preparing to present figures roughly two to three percent above actual performance to senior managers.
An email in that process said, in substance, that a +3% data set would be sent for the time being.
Engineers said the HC-SCR approach was difficult. The executive response began from the premise that “we can't” was not the answer
In 2014, development of the A05C engine faced a difficult combination of emissions performance, weight and cost if the planned HC-SCR exhaust-cleaning system was retained. Engineers raised the difficulty with the executive responsible for development while considering another after-treatment approach.
The response was not to accept that the approach could not be made to work, but to have research, design and testing cooperate to find a way to make it viable.
Hino then created what it internally called a large-room project, bringing people from several technical groups into one room to work through the problem.
Employees had a name for being made to explain a problem in front of a large meeting: the “stage”
A term equivalent to “the stage” appeared repeatedly in employee questionnaires and interviews.
It referred to a situation where the person or department responsible for a problem had to explain the cause and response in a meeting attended by many other departments.
The committee saw the everyday use of this term as suggesting a culture of ignoring a troubled department to avoid being affected by its problems, rather than offering help.
Statement recorded by the committee
Employee survey response · Site translation from the Japanese report
We called it the ‘stage,’ but if a problem came to light and we could not meet the deadline, we had to explain the situation in front of the department responsible for overseeing development progress, and the individual employee in charge would be held responsible.
Employees described a culture where raising a problem could mean becoming the person responsible for fixing it
Employee survey answers said that pointing out an issue could result in the person who raised it being assigned the work of resolving it.
One expression recorded in the report can be translated as “the one who speaks up loses.”
One survey answer said that because speaking up meant having to act, employees tended to avoid pointing out problems unless they were personally affected. The committee presented these answers as criticism of a culture of avoiding trouble.
Employees said honestly reporting an impossible target could make them look less capable
The committee highlighted repeated concerns in the employee survey about evaluation and promotion. Respondents described a belief that people who simply aligned with senior expectations were favored, while someone who candidly reported that a target was impossible or very difficult risked being judged as less capable.
By contrast, employees perceived that saying they would push through the target—or presenting results in a way that looked successful—could be rewarded.
Another survey response noted that proving why something could not be done consumed so much time that employees sometimes prioritized the work itself instead of escalating the impossibility.
The committee's conclusion was stark: an organization unable to say “this cannot be done” can end up achieving the impossible through misconduct
The committee pointed to Hino’s strongly top-down culture, where lower-level staff reacted intensely even to casual remarks by senior people. It discussed a case where managers accepted a late demand for better fuel economy despite the actual capability and schedule making the demand difficult, passing that pressure down to the testing organization.
The committee said that when people cannot say that something cannot be done, an imposed impossibility can ultimately be “achieved” through misconduct.
A method for making fuel economy look better had become shop-floor know-how
The committee found that rules and work manuals were often incomplete and that knowledge transfer relied heavily on on-the-job training.
Within that environment, manipulating the calibration value of a fuel-flow meter was used as a practical method for improving the apparent fuel-economy result.
The report treats this as an example of informal shop-floor knowledge becoming a mechanism for misconduct when efficiency and immediate outcomes override formal controls.
Eight measurements taken at the middle point were redistributed as beginning, middle and final test data
When discussing off-road engine durability testing, the committee said some practices were especially crude compared with the on-road engine cases.
In one example, eight measurements taken at an intermediate point were divided up and presented as data from the beginning, middle and end of the durability test.
The committee questioned whether the people carrying out a test that required roughly 2,000 hours understood what the durability test was actually intended to establish.
Investigation committee finding
The Special Investigation Committee's assessment · Site translation from the Japanese report
One typical example is how measurement data were handled in the E13C-YM's RMC mode: eight measurements taken at the intermediate one of three measurement points were allocated to the initial, intermediate and final measurement points. Compared with on-road engines, the methods could be described as bold, crude and sloppy.
What the report says about the background
The committee pointed to plans that did not match available resources and capability, an excessively top-down culture, weak psychological safety, organizational silos, insufficient separation between development and certification, and poor rule and data management.
What stands out is how thoroughly the report documents what happened when people said a target was difficult and how employees expected to be treated when they surfaced a problem. From Reports distinguishes those survey and interview statements from verified acts and from the committee’s own causal conclusions.
Corrections to this article
Note 01 now identifies the two-to-three-percent uplift as the committee’s inference and cites pp.111–112. Note 02 also cites p.152 for context. Note 03 now reflects the committee’s assessment of ignoring a troubled department to avoid being affected, replacing the previous wording about exposing the problem owner. Note 04 attributes the explanation about speaking up to a survey response (pp.243–244).