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Report on Fuel Economy and Emission Testing Confirms No Improper Alteration or Falsification of Test Data by Mazda

WASHINGTON, Aug. 9, 2018 /CNW/ - Following a request made by Japan's Ministry of Land, Infrastructure, Transport and Tourism (MLIT) issued to Japanese automakers on July 9, 2018 after the discovery of fraudulent testing practices at other companies, Mazda Motor Corporation submitted a report to MLIT on the results of an investigation into its sample testing of fuel economy and emissions during final vehicle inspections.

Mazda Canada Inc. (CNW Group/Mazda Canada Inc.)

The investigation covered JC081 and WLTC2 testing modes and the key findings of the report are:

  1. No improper alteration or falsification of test data in either mode.
  2. Test data containing speed trace errors* was found in 72 cases out of 1,472 vehicles tested under the JC08 mode.  The company has identified two reasons for these errors. Firstly, the system was not set up to automatically invalidate results when a speed trace error occurred. Secondly, test procedures left the determination of speed trace errors up to each individual inspector.
  3. All test data has been re-examined and the results show there was no effect on specification fuel economy and emission figures. No such cases were found in WLTC mode testing.

This incident concerns only vehicles sold in Japan, and export vehicles are not applicable for this incident. Export vehicles are tested in accordance with the regulations of the market to which they are exported.

Mazda has decided to take the following steps to prevent a reoccurrence:

  • The system will be updated to automatically treat test results as invalid in the event of a speed trace error.
  • Mazda has increased the number of employees who check inspection data, including speed trace errors.

Mazda accepts that errors were made on a small number of tests and the situation was identified quickly and steps have been put in place to avoid it happening in the future.

Items investigated and results

Items investigated


No. of vehicles


No. of vehicles



of total

Improper alteration of reported
fuel economy and emissions data

Not found

466 units

JC08: 39 units [1]

WLTC:427 units [3]

0 units


Improper alteration of
temperature/ humidity data in
the emissions testing room

Not found

466 units

JC08:39 units


0 units


Data judged valid despite deviations from stipulated test conditions

Speed trace deviation



JC08:1,472 units [2]

WLTC:403 units [4]

72 units

JC08:72 units

WLTC:0 units





Not found

466 units

JC08:39 units

WLTC:427 units

0 units


Failure to calibrate emissions
gas analyzer

Not found

5,310 units

JC08:5,285 units

WLTC:25 units

0 units



Mazda Canada Inc. is responsible for the sales and marketing, customer service and parts support of Mazda vehicles in Canada. Headquartered in Richmond Hill, Ontario, Mazda Canada has a nationwide network of 164 dealerships. For additional information visit Mazda Canada's media website at

*A situation in which vehicle speed deviates more than the permitted amount from the speed trace pattern prescribed by the test mode


SOURCE Mazda Canada Inc.

For further information: Sandra Lemaitre, Mazda Canada Inc., 905-787-7167 ; Chuck Reimer, Mazda Canada Inc., 905-787-7079

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