The Environmental Protection Agency ordered Mitsubishi to further inform them on their US models, after the Japanese company announced their improper fuel economy testing of their vehicles in Japan for the last 25 years.

The agency is coordinating their actions with the California Air Resources Board, reports AutoNews. Mitsubishi was also ordered to retest the models sold in the US from now on.

US regulators now want Mitsubishi to retest their vehicles sold in the US by conducting additional coast down tests on them. During this test, a car coasts to a stop from 80mph, getting data this way from its aerodynamic drag and drivetrain friction. The data is then used to program dynamometers in simulating a car’s behavior on real roads during indoor testing.

The Japanese company admitted that they have been measuring the fuel economy of their models in Japan incorrectly since 1991. More specifically, they said that the have been using a different method for Japan’s official “coasting test”, with Mitsubishi’s half market value being wiped out since the news originally broke out.

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