Mazda admits to fuel economy and emissions testing errors

Mazda Motor Corporation has submitted the results of an investigation into its fuel economy and emissions testing during final vehicle inspection, in response to a request by Japan's Ministry of Land, Infrastructure, Transport and Tourism (MLIT).

The results of the investigation show some models produced at Mazda's Hiroshima Plant were inappropriately handled in 72 cases, when tested under the JC08 standard.

MLIT issued a request for carmakers to internally investigate their procedures on July 9 after fraudulent testing practices were discovered at other companies.

Mazda launched an investigation into its JC08 and WLTC emissions testing procedures implemented over the last three years and nine months; the amount of time that carmakers are legally required to keep records.

The investigation found that JC08 test data containing "speed trace errors" were handled inappropriately in 72 cases out of the 1472 units tested, however no such cases were found in WLTC testing.

A speed trace error is when a vehicle's speed deviates more than is allowed under the given testing regulation.

According to Mazda, these findings have no effect on fuel economy and emission figures, and no improper alteration or falsification of test data was discovered.

To prevent this from happening again, Mazda Motor Corporation says it will now treat test results as invalid when a speed trace error is found.

The probe that prompted Mazda to confess to improper testing has also outed other Japanese carmakers in recent times.

Nissan and Subaru also discovered falsified fuel economy and emissions data internally, caused in both cases by the use of unqualified inspectors in final vehicle checks.

Should governments put more pressure on carmakers and their testing procedures? Tell us your thoughts in the comment section below.