The affected cars are four mini-car models: the “eK Wagon” and “eK Space” manufactured by MMC; and the “Dayz” and “Dayz Roox” manufactured by MMC and supplied to Nissan Motors Corporation (NM) since June 2013. Up until the end of March 2016, MMC has sold 157,000 of the eK Wagon and eK Space and supplied 468,000 units of the Dayz and Dayz Roox to NM.

Because 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, Nissan examined the fuel consumption rates of the applicable cars for its own reference and found deviations in the figures.

Nissan then requested MMC to review the running resistance value—the rolling resistance mainly generated by the tires and the air resistance while the vehicle is in motion—set by MMC during tests by MMC.

Mitsubishi said that during the course of this review, it learned that the running resistance value used for testing provided more advantageous fuel consumption rates than the actual rates.

Mitsubishi Motors has stopped production and sales of the applicable cars. Nissan also has stopped sales of the applicable cars, and MMC and Nissan will “discuss compensation” regarding this issue.

Mitsubishi Motors also said that during its internal investigation, it found that the testing method which was different from the one required by Japanese law had been applied to other models manufactured by MMC for the Japanese domestic market.

Mitsubishi is also beginning an investigation into products it manufactured for overseas markets. In order to conduct an investigation into these issues objectively and thoroughly, it will set up a committee consisting of only external experts. The company said it will publish the results as soon as the investigation is complete.