With Mitsubishi having succumbed to its recent scandal and amidst a growing concern over fuel economy claims, manufacturers are asked by the Japanese government to further investigate any potential anomalies with their vehicles. And now another one has come forward.

Suzuki now reports that they have been using non-compliant fuel economy tests to determine efficiency values for their vehicles. Suzuki’s spokesman Hidehiro Hirano announced that the company’s chairman, Osamu Suzuki, will report the problem to Japan’s Ministry of Land, Infrastructure, Transport and Tourism (MLIT).

In their statement, Suzuki claims the issue concerns 16 vehicles currently sold in their home market. These vehicles appear to have been tested with standards that are not up to par with regulations set by the MLIT. It’s important to note however, that Suzuki did not at all tamper nor manipulate the test results.

Having analyzed the process by which they measure the fuel economy of the 16 cars, Suzuki eventually discovered the issue. It seems the discrepancies appeared in the fact that Suzuki has summed up their fuel efficiency values based on a build-up of measured data from individual components of the cars instead of performing an actual coasting test.

Suzuki continued the investigation, comparing the two sets of results that showed “all certified values remain within the range of measurement deviation.” While the company admits that there is a discrepancy in values compared to the correct tests, they believe that it should not pose a significant problem for their end-users. The fourth largest Japanese auto-manufacturer also mentions the fact that their testing area in Sagara is on top of a hill by the sea, thereby introducing different weather conditions such as strong winds that may affect test values.

The following 16 models were affected by the test anomaly:

-       Alto

-       Alto Lapin

-       Wagon R

-       Hustler

-       Spacia

-       Every

-       Carry

-       Jimny

-       Solio

-       Ignis

-       Baleno

-       SX-4 S-CROSS

-       Escudo 2.4

-       Swift

-       Escudo

-       Jimny Sierra

Shortly after their revelation, Suzuki’s shares dropped 11% during afternoon stock trades in Japan.