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Tokyo, April 26, 2016
Regarding the Report to MLIT Concerning Improper Conduct in Fuel Consumption Testing of Vehicles Manufactured by Mitsubishi Motors Corporation
The following is a summary of the report submitted by Mitsubishi Motors Corporation (MMC) to the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) today, pursuant to instructions received from MLIT on April 20 to investigate improper conduct in fuel consumption testing of vehicles manufactured by MMC.
Report Summary
Background to the improper conduct of MMC mini-car fuel consumption testing data
Four grades of the model year 2014 eK Wagon and Dayz (submitted in February 2013) were produced—a fuel-economy grade, a standard grade, a turbo grade and a 4WD grade. During development of the fuel-economy grade, the fuel consumption target, which had initially been 26.4km/l (in February 2011), was revised upward over a series of internal meetings until finally being set at 29.2km/l (February 2013).
Driving resistance data were obtained for that fuel-economy grade using a "high-speed coasting test," which differed from the coasting test required by the applicable laws and regulations in Japan. A relatively low value was selected from among the test results for use as the driving resistance value in order to give the appearance of greater fuel consumption. Data for the remaining three grades were calculated without testing based on the data for the fuel-economy grade.
The data submitted for the model year 2014 eK Space and Dayz Roox (submitted in October 2013), the model year 2015 eK Wagon and Dayz (submitted in March 2014), the model year 2015 eK Space and Dayz Roox (submitted in December 2014), and the model year 2016 eK Wagon and Dayz (submitted in June 2015) were all calculated without testing based on the data for the model year 2014 eK Wagon and Dayz to achieve the fuel consumption targets.
The following is the timeline leading up to the use of the "high-speed coasting test" differing from the test required by the applicable laws and regulations in Japan. We are currently investigating the reasoning behind each of the decisions outlined below.
In 1991, the coasting test was designated as the method for testing driving resistance under the Road Transport Vehicle Act, but MMC began testing vehicles for the Japanese market using a different method, the "high-speed coasting test".
In January 1992, a method was developed to reverse-calculate coasting time using driving resistance.
In January 2001, a test was run that compared the coasting test to the "high-speed coasting test," and the difference in results was found never to exceed 2.3%.
In February 2007, the testing manual was updated to add that "TRIAS (i.e., the coasting test) is to be used for DOM (i.e., vehicles for sale in Japan)." Nevertheless, the "high-speed coasting test" continued to be used thereafter.
Future direction of investigations
While some progress has been made in investigating the events described in sections 1 and 2 above, we will continue to work to discover the causes of this improper conduct and who is responsible.
Sufficient investigation has not been made into MMC vehicles other than the mini-cars described above; we plan to submit a separate report after looking into those models.

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