Mazda, Suzuki and Yamaha improperly tested fuel economy and emissions

Jimi Beckwith
9 August 2018
Follow @@JimiBeckwith

Several manufacturers in Japan have been found to have improperly tested cars for emissions and fuel economy in an investigation ordered by the Japanese government after the discovery of Nissan and Subaru"s emissions testing impropriety last year. 

Suzuki, Mazda and Yamaha are implicated, although with different levels of severity. 

Mazda released a statement explaining that “Test data containing speed trace errors was found in 72 cases out of 1472 vehicles tested under the JC08 mode.”

The company’s emissions testing system “was not set up to automatically invalidate results when a speed trace error occurred,” it explained, while the level of deviation permitted under the test was at the discretion of each individual inspector. 

As a result, there is no false data in any of Mazda’s test data from either test mode. The company has dealt with the findings by updating its testing system to invalidate test results if a speed trace error is detected, as well as increasing the number of workers checking the data.

Suzuki UK is awaiting a statement from the company"s headquarters in Japan, but Reuters reports that Suzuki admitted to around 6400 cars being improperly inspected, stretching back as far as June 2012. 

“I deeply apologise and will lead efforts to prevent recurrence,” said Suzuki boss Toshihiro Suzuki. No recalls are planned, however, as Suzuki says that no significant problems were found. 

Yamaha is also implicated, but only 2% of inspections on the brand"s motorbikes were carried out improperly. 

Autocar is awaiting further comment from Suzuki and Yamaha.