Mitsubishi admits falsifying fuel economy tests for 25 years

In 2014 Nissan launched the new Nissan Dayz Roox, based on a vehicle supplied by Mitsubishi Motors - image courtesy of Nissan.
In 2014 Nissan launched the new Nissan Dayz Roox, which was supplied by Mitsubishi Motors and is now part of the investigation into Mitsubishi's use of false fuel economy data - image courtesy of Nissan.

Mitsubishi Motors Corporation has admitted to intentionally lying about fuel economy data for four of its models dating back to 1991.

The Japanese automaker acknowledged that it had intentionally used fuel consumption tests for some of its models that did not comply with Japanese regulations. This resulted in inaccurate fuel economy data for four minicar models that were sold in Japan.

The minicar models involved in the inaccurate mileage tests include 157,000 of Mitsubihi’s eK Wagon and eK Space passenger cars and 468,000 Dayz and Dayz Roox vehicles produced by Mitsubishi for Nissan (pictured).

An internal investigation found that the incorrect Mitsubishi Motors’ fuel economy data dated back to 1991, when the “high-speed coasting test”, which differed from the testing required by Japanese regulations, was designated by Mitsubishi Motors as the method for testing driving resistance.

Mitsubishi Motors executive vice president Ryugo Nakao said the company should have followed the regulation changes in 1991, which required testing methods to better reflect stop-start urban driving.

“We should have switched, but it turns out we didn’t,” he said.

Mr Nakao said that rising fuel economy targets may have played a part in the perceived pressure to cheat on the fuel consumption tests as a way of meeting the internal demands.

“Judging by what the investigations have shown so far, it seems there was pressure,” he said.

Mitsubishi Motors raised its fuel economy targets five times in two years while developing the mini-vehicles, reaching 29.2 km/L from an initial target of 26.4 km/L.

Mileage fraud breaks Japan’s fuel efficiency laws due to buyers being eligible for tax breaks if a vehicle model has good mileage and Mitsubishi Motors is likely to face financial penalties as a result of the breach.

Nissan revealed the inconsistencies

Mitsubishi Motors admitted to cheating on the fuel efficiency results for its minicar models after Nissan raised concerns and pointed out inconsistencies in consumption data.

In the wake of the recent revelations Mitsubishi said in a statement that it had decided to “stop production and sales” of the applicable cars and that Nissan had also stopped sales of the affected vehicles. The company said it would “discuss compensation regarding this issue” directly with Nissan.

Mitsubishi also said it plans to expand its internal investigation to check the validity of consumption figures produced for vehicles manufactured for overseas markets.

Mitsubishi Motors plans to conduct an investigation into the fuel economy testing issues by setting up a special investigation committee consisting of only external experts, and will publish the results as soon as the investigation is completed.

Not the first scandal for Mitsubishi

The admission of tampering with tests comes 15 years after Mitsubishi Motors was involved in a huge scandal that involved a systematic cover up of vehicle defects, which dated back to the 1970s and included failing brakes, faulty clutches and fuel tanks that were prone to falling off.

Mitsubishi Motors’ recent scandal comes in the same 12 month period in which German automaker Volkswagen admitted it had cheated tests on some of its diesel models around the world.

The Mitsubishi Motors revelations has seen a dramatic drop in the company’s share price, sliding almost 50% since the scandal first surfaced.

Resignations are expected from high up in the company with some commentators suggesting that both chief executive Osamu Masuko and chief operating officer Tetsuro Aikawa may step down.