Mitsubishi has admitted to tampering with fuel consumption rates in four of its Kei-car models manufactured in Japan. The cars affected are the 660-cc Mitsubishi eK Wagon and eK Space, and the Dayz and Dayz Roox models, which the automaker produces for Nissan.
In an official statement, Mitsubishi says it has rolled out 157,000 units of the eK Wagon and Space, and 468,000 units of the Dayz and Dayz Roox from its Mizushima plant in Okayama. The company divulges that the testing method used was different from the one required by Japanese law, resulting in inconsistencies in the fuel consumption rates.
The error was first identified by Nissan, who then requested Mitsubishi to investigate the matter. The automaker reveals that the improper conduct in the testing was related to altered tyre pressure, which leads to more favourable figures in terms of fuel efficiency.
Mitsubishi confirms it has put a halt to the production of the affected models, while Nissan has stopped selling the cars. Both automakers will set up an internal committee to investigate the misconduct, including models manufactured for foreign markets.
Improper conduct in fuel consumption testing on products
manufactured by Mitsubishi Motors Corporation (MMC)
In connection with the certification process for the mini-cars manufactured by MMC, we found that with respect to the fuel consumption testing data submitted to the Ministry of Land, Infrastructure, Transport and Tourism (MLIT), MMC conducted testing improperly to present better fuel consumption rates than the actual rates; and that the testing method was also different from the one required by Japanese law. We express deep apologies to all of our customers and stakeholders for this issue.
The applicable cars are four mini-car models, two of which are the “eK Wagon” and “eK Space” which have been manufactured by MMC; and the other two are the “Dayz” and “Dayz Roox” which have been manufactured by MMC and supplied to Nissan Motors Corporation (NM) since June 2013. Up until the end of March 2016, MMC has sold 157 thousand units of the eK Wagon and eK Space and supplied 468 thousand units of the Dayz and Dayz Roox to NM.
Since MMC developed the applicable cars and was responsible for obtaining the relevant certifications, MMC conducted fuel consumption testing. In the process of the development for the next generation of mini-car products, NM examined the fuel consumption rates of the applicable cars for NM’s reference and found deviations in the figures. NM requested MMC to review the running resistance(*) value set by MMC during tests by MMC. In the course of our internal investigation upon this request, MMC learned of the improper conduct that MMC used the running resistance value for testing which provided more advantageous fuel consumption rates than the actual rates. MMC will sincerely respond to our customers who own and use the applicable cars.
(*) running resistance: rolling resistance (mainly generated by tires) and air resistance while vehicles are moving
We have decided to stop production and sales of the applicable cars. NM also has stopped sales of the applicable cars, and MMC and NM will discuss compensation regarding this issue.
During our internal investigation, we have found that the testing method which was different from the one required by Japanese law has been applied to other models manufactured by MMC for the Japanese domestic market.
Taking into account the seriousness of these issues, we will also conduct an investigation into products manufactured for overseas markets.
In order to conduct an investigation into these issues objectively and thoroughly, we plan to set up a committee consisting of only external experts. We will publish the results of our investigation as soon as it is complete.