Mitsubishi: We've been cheating emission tests since 1991

Mitsubishi Motors own emissions crisis has deepened last night when the car-maker was forced to admit it had used the wrong emissions test in Japan since 1991.

The falsified data, so far, only concerns its Japan-only mini-car range.

The discrepancy arose following a revised emissions tests was introduced back in 1991 to better reflect the stop-start nature of urban driving.

Mitsubishi now admits it ignored the 1991 rules and carried on testing under the old regime.

"We should have switched, but it turns out we didn't," said Ryugo Nakao, executive vice-president.

Things got worse for the car-maker when senior execs declared yesterday that they themselves didn’t know the extent of the emissions crisis.

Tetsuro Aikawa, Mitsubishi Motors' president, said an inquiry led by three external lawyers had been opened: "We don't know the whole picture and we are in the process of trying to determine that. I feel a great responsibility."

At the end of Tuesday trading this saw another 10 per cent wiped off the share value, contributing to an incredible 50 per cent wiped off the value of car-maker since the crisis began.

So far, it’s being reported, that 157,000 eK Wagon and eK Space models and 468,000 Dayz and Dayz Roox produced for Nissan have been affected.

Mini-cars in Japan attract substantial tax breaks based on their tiny 660cc engine’s fuel consumptions.

Mitsubishi Motors Australia (MMAL) has already issued a statement clarifying none of the mini-cars that cheated the later regulations have ever been sold in the Australian market.

This is not the first scandal Mitsubishi has been embroiled in.

Back in 2000 the car-maker admitted to covering up safety records and customer complaints. Four years later it admitted to safety defects going back to 1977 causing some commentators to claim the corporate scandal was one of the largest in Japanese history.

The new deception is expected to now see the Japanese government wade in.

Already described as “extremely serious” by minister for transport, Keiichi Ishii, the Japanese cabinet will now wait for the hearings of an internal investigation of the faked data before making a decision that could involve police raids and high-profile arrests.