Mitsubishi Motors has admitted to manipulating fuel economy tests — Quartz

Mitsubishi Motors said today (April 20) it manipulated fuel economy tests for 625,000 vehicles produced from 2013. According to Kyodo News (paywall) the deception involved tweaking figures when applying pressure on tires during tests, resulting in the cars appearing more fuel efficient.

Nissan recently discovered the inaccuracies in two models it outsources to Mitsubishi Motors after spotting discrepancies with its own tests. Mitsubishi Motors said an additional two models sold under its own brand are also affected. The models involved include Mitsubishi’s eK minicar, which Nissan sells as the DayZ in Japan. Nearly 470,000 Nissan cars are involved, compared to 157,000 sold by Mitsubishi. The two companies are discussing compensation.

All the models are “minicars” sold in Japan. Mitsubishi said it will investigate whether any overseas models are are affected.

Mitsubishi Motors shares plummeted 15% after the admission—and things could get worse. After investigators caught Volkswagen cheating on emissions tests last year, the German automaker suffered heavy losses, including a 25% drop in US November sales from the previous year.

Other carmakers have also made mistakes regarding fuel economy or emissions. Ford was forced to lower fuel economy ratings for its hybrid models a few years ago, and South Korean carmakers Hyundai and Kia paid fines in late 2014 to settle US claims they overstated mileage ratings.

The admission is another hit for for corporate Japan, which has seen Sharp sold to Taiwan’s Foxconn and Toshiba receiving a record fine in December for massive accounting irregularities (paywall).