TOKYO • Mitsubishi Motors admitted yesterday it has been using an improper fuel-efficiency testing method for 25 years and did not know how many cars were affected, widening a data-cheating scandal that has plunged it into crisis.
The latest twist will likely fuel speculation that the misconduct stretched to vehicles sold overseas and will send the number of affected vehicles soaring from the more than 600,000 already known.
"For the domestic market, we have been using that method since 1991," Mitsubishi vice-president Ryugo Nakao told a Tokyo news briefing. "But we don't know the number of models" affected in total, he added.
Last week, Mitsubishi admitted unnamed employees rigged tests to make some of its cars seem more fuel-efficient than they really were. It said at the time the rigged testing dated back to 2002.
The firm's Tokyo-listed shares have been in free fall since the story broke last Wednesday, losing about half their value.
Mitsubishi president Tetsuro Aikawa has acknowledged that the crisis would damage the firm's finances and told yesterday's briefing: "I can only apologise."
Officials at the news conference said the company did not change its fuel-efficiency testing method when the Japanese government ordered the industry to use an updated system years ago.
So far, the testing has affected vehicles sold in Japan involving four mini-car models, including cars made for rival Nissan.
A spokesman for Cycle & Carriage Automotive said last week models sold in Singapore were not affected.
The embarrassing revelations have raised questions about the Japanese carmaker's future, and pointed to a broader problem in the global car industry as regulators probe other carmakers' pollution and fuel-efficiency standards.
German carmaker Volkswagen said last Friday the engine-rigging scandal it is currently engulfed in pushed it into its first annual loss in more than 20 years, and the final costs are still not calculable.
Also last Friday, German Transport Minister Alexander Dobrindt said a probe sparked by Volkswa- gen's emissions-rigging scandal found irregularities at 16 car brands, including Mercedes, France's Renault, Alfa Romeo, Chevrolet, Hyundai, Jaguar and Nissan.