Suzuki Motor Corp. on Wednesday became the latest automaker to admit mistakes in measuring car fuel economy, saying it has been using an unapproved system for determining performance.

The automaker said an internal investigation, conducted in light of Mitsubishi Motors Corp.'s admission of data falsification, found that road and air resistance figures for its entire current range of 16 models were obtained this way.

Regulations require vehicles to be tested on the road, but Suzuki used data obtained from laboratory-style testing of individual components, such as the tires, brakes and transmission.