Mitsubishi cheated fuel economy tests

Mitsubishi Motors Corporation has confessed to understating the fuel consumption of at least 625,000 mini-cars sold in Japan by manipulating the federal fuel consumption test.

In a press statement issued this evening, the Japanese car-maker said it will appoint independent investigators to determine the extent of the fuel consumption cheat, which Mitsubishi admits affects other models in Japan, in vehicles sold in export markets including Australia.

The fuel efficiency scandal, for which Mitsubishi's global president Tetsuro Aikawa and two other executives bowed in apology at a briefing in Tokyo, could reach Volkswagen Dieselgate-style proportions, with Mitsubishi Motors Corporation shares falling 15 per cent -- the most in more than a decade -- in Tokyo trading after the announcement.

Mitsubishi also said it is discussing compensation with Nissan, which discovered the fuel test manipulation in two Nissan-badged mini-cars supplied by Mitsubishi for the Japanese market, where sales and production of four mini-cars has ceased.

So far, confirmed affected vehicles include the Nissan Dayz and Dayz Roox, of which 468,000 have been sold in Japan since June 2013, and the Mitsubishi eK Wagon and eK Space, of which 157,000 have been sold.

"Mitsubishi Motors Australia (MMAL) has been informed of a certification process issue affecting four mini-car models manufactured by Mitsubishi Motors for the Japanese domestic market," said MMAL in a statement.

"MMAL wishes to clarify that none of these mini-car models are sold in the Australian market.

"Our parent company has found that the same testing method has been applied to other models manufactured by MMC for the Japanese domestic market.

"Taking into account the seriousness of this issue, MMC has advised it will also investigate products manufactured for overseas markets.

"This investigation will be conducted by a committee of experts operating independently of Mitsubishi Motors.

"In the meantime, MMAL will continue to monitor the situation closely."

In 2014, Korean car-makers Hyundai and Kia paid substantial fines and forfeited emissions credits to settle claims they overstated official economy figures.

In its statement, Mitsubishi admitted it breached Japanese law and apologised to its customers for misleading them. It said it manipulated test protocol by reducing vehicle rolling and air resistance.

"In connection with the certification process for the mini-cars manufactured by MMC, we found that with respect to the fuel consumption testing data submitted to the Ministry of Land, Infrastructure, Transport and Tourism (MLIT), MMC conducted testing improperly to present better fuel consumption rates than the actual rates; and that the testing method was also different from the one required by Japanese law.

"Since MMC developed the applicable cars and was responsible for obtaining the relevant certifications, MMC conducted fuel consumption testing. In the process of the development for the next generation of mini-car products, NM examined the fuel consumption rates of the applicable cars for NM's reference and found deviations in the figures.

"NM requested MMC to review the running resistance value set by MMC during tests by MMC. In the course of our internal investigation upon this request, MMC learned of the improper conduct that MMC used the running resistance value for testing which provided more advantageous fuel consumption rates than the actual rates. MMC will sincerely respond to our customers who own and use the applicable cars.

"During our internal investigation, we have found that the testing method which was different from the one required by Japanese law has been applied to other models manufactured by MMC for the Japanese domestic market.

"In order to conduct an investigation into these issues objectively and thoroughly, we plan to set up a committee consisting of only external experts. We will publish the results of our investigation as soon as it is complete."