Mitsubishi Motors Corporation (MMC) has announced that company president Tetsuro Aikawa will step down from his post after the carmaker was embroiled in a scandal involving rigged fuel economy tests. MMC company Chairman and CEO Osamu Masuko will be serving as interim president. Executive vice president Ryugo Nakao has also filed his resignation in relation to the issue.

A statement from MMC explained the reason for the two executives' resignation from the company.

"As our announcement today on the Report to the Ministry of Land, Infrastructure, Transport and Tourism concerning improper conduct in fuel consumption testing of vehicles manufactured by MMC shows, MMC has caused tremendous trouble and concern to our customers and all of our stakeholders. Considering this, Mr. Aikawa and Mr. Nakao decided today that they will resign as Representative Directors as of June 24, 2016," said Mitsubishi.

The date of their resignation has been slated for June 24 during the shareholder's meeting.

The inconsistency was uncovered by Nissan engineers when they noticed the Dayz was not matching the fuel economy ratings achieved by the kei car's twin, the Mitsubishi eK Wagon. A joint investigation was launched by the two automakers and soon after, Aikawa issued a public apology saying that the company has been overstating fuel economy figures for the past 25 years.

Since 1991, MMC has been applying what was called the high-speed coasting test which was based on a method called the coast down test. The coast down method is primarily used for testing aerodynamic, mechanical and rolling resistance but not fuel economy.

In their statement regarding the high-speed coasting test, Mitsubishi had this to say.

"With respect to the reason why MMC adopted, in 1991, a 'high-speed coasting test' which differed from the coasting test required by the Road Trucking Vehicle Act, MMC interviewed the persons in charge at the time, including retired employees, but no clear-cut answer was obtained in this regard. However, MMC assumes that the reason why it continued to use a "high-speed coasting test" even though there were several chances to replace it with the coasting test is that previous test result gave only 2.3% at the maximum."

After the public apology of Aikawa, there were soon talks of Nissan buying a stake in Mitsubishi Motors. Less than 48 hours after the initial reports were made, Nissan then confirmed that they have bought a 34 percent stake in Mitsubishi Motors, making them the largest shareholder in the company.