TOKYO, April 20 (UPI) -- Mitsubishi Motors has admitted falsifying fuels economy data for about 625,000 ultrasmall vehicles sold in Japan -- the latest scandal hitting the automobile industry.
The models affected were for vehicles starting in 2013, but Mitsubishi President Tetsuro Aikawa said at a news conference Wednesday that other models might have violated Japanese standards.
"It has become clear that improper testing methods were used to improve the appearance of fuel efficiency," Aikawa said before he and other company leaders bowed in apology. Company executives called the manipulation of tests on the microcar, called the eK, "intentional."
Although he was unaware of the regularities, he said, "I feel responsible."
The inaccurate data affected 157,000 of its cars and 468,000 produced for Nissan under the Dayz and Dayz Roox brand. The Mitsubishi models were the ek wagon and eK Space.
These small have 660cc petrol engines. They are popular in Japan but not successful in other markets.
The company is Japan's sixth-largest car maker and sold more than 1 million vehicles last year.
The issue was reported to Japan's transportation ministry and Nissan told dealers to stop selling the affected vehicles. Countries have different rules for fuel-economy testing.
The calculation involved the way Mitsubishi calculated the affect of wind and tire resistance on the car during simulations. The company said it used a method than can produce lower resistance and make them appear to travel farther on less fuel.
Shares in Mitsubishi Motors closed down 131 yen at 733 yen in Tokyo --- its biggest one-day fall in nearly 12 years.
This is the first time that a Japanese car maker has reported misconduct involving fuel economy tests.
In 2014, South Korea's Hyundai and its affiliate, Kia, agreed to pay $350 million for overstating their vehicles' fuel economy ratings. They also resolved claims from car owners.
Last year, Volkswagen was found to have cheated diesel emissions tests worldwide.