MAZDA Motor Corporation has admitted to errors in its sample testing of fuel economy and emissions, however it did not find evidence of cheating after conducting an internal investigation that has now been reported to the Japanese ministry of land, infrastructure, transport and tourism (MLIT).
Specifically, the JC08 and WLTC cycles were used to test samples of vehicles undergoing final inspections during manufacturing, but Mazda says there was “no improper alteration or falsification of test data” found in either cycle.
However, speed trace errors were found in 72, or 4.9 per cent, of 1472 vehicles tested using the JC08 cycle, meaning these samples deviated more than permitted amount from the preset speed trace pattern.
The investigation revealed that these speed trace errors were caused by incorrect programming for the system that should automatically invalidate such results.
Additionally, test procedures were not organised properly, with the detection of speed trace errors made the responsibility of each individual inspector.
Nonetheless, after revisiting all of the related test data, Mazda has found “there was no effect on specification fuel economy and emission figures”. It added that no errors were found with the WLTC test cycle.
To prevent such a situation from reoccurring, Mazda has updated the aforementioned system to automatically invalidate test results when speed trace errors are detected.
Mazda has also increased the number of employees responsible for checking inspection data, such as speed trace errors, meaning it will no longer fall to an individual.
“We would like to offer our sincere apologies for the concern this matter has caused to our customers and to all our stakeholders,” Mazda said in the MLIT report.
“We are treating the matter very seriously and will make every effort to prevent similar occurrences in the future.”
The investigation, which covered the period from November 2014 to July 2018, only involved Mazda’s Minami-Ku plant in Hiroshima, which is currently responsible for producing the Mazda3, Mazda6, CX-5, CX-9, MX-5 and Abarth 124 Spider for global markets.
However, overseas reports have suggested that the speed trace errors were limited to vehicles produced for the Japanese market. As such, the impact on Australian vehicles, if any, is unknown.
Mazda joins Nissan, Mitsubishi, Subaru and Suzuki as Japanese car-makers that have recently had the fuel economy and emissions of their vehicles called into question, prompting MLIT to mandate internal investigations on July 9 this year.
The intense focus on the testing standards of the automotive industry began when Volkswagen Group admitted to fitting some of its diesel vehicles with emissions cheat devices in August 2015.
Meanwhile, Yamaha Motor, which produces motorcycles and boats alongside other products, has confirmed misconduct of its own, after it released a statement that said: “Regarding the emissions inspections... it is a fact that there were improper actions. We sincerely apologise.”