Mazda, Suzuki and Yamaha admit to falsifying emissions test data

The three Japanese car manufacturers certified products inspected under invalid conditions

Suzuki said inspections on almost half of 12,819 new cars across three plants were carried out incorrectly (Suzuki)

Japanese car Mazda, Suzuki and Yamaha companies have admitted to conducting improper emissions tests on their vehicles.

The findings came after Japan’s transport ministry ordered 23 car manufacturers to examine their procedures following admissions from Nissan and Subaru that fuel economy data had been falsified.

Mazda, Suzuki and Yamaha all said that they had certified products that were inspected under invalid conditions. Suzuki said inspections on almost half of 12,819 new cars across three plants were carried out incorrectly.

Impropriety was much less common at the other two manufacturers, with 72 of Mazda’s sample vehicles and 7 of Yamaha’s motorbikes tested wrongly.

“Mishandlings found in so many vehicles were a serious problem, and we take it very seriously,” Suzuki Motor president Toshihiro Suzuki told a news conference.

“The checking mechanism was insufficient. We regret that we left the inspections to factories,”

He apologised to the company's customers and business partners for the issues but said Suzuki would not be issuing a recall because the actual fuel efficiency of vehicles was not affected.

The revelations form part of a growing scandal over product inspections in Japan.

Japanese prosecutors charged major steelmaker Kobe Steel for falsifying quality tests for years, affecting hundreds of companies that had bought from the company to make a range of products including vehicles, aircraft and appliances.

Yamaha shares were down almost 5 per cent on Tuesday, Suzuki was down 6 per cent and Mazda 1.3 per cent.