Now it's Mitsubishi Motors that admits it put its thumb on the scale or, more precisely, manipulated test data to improve mileage ratings on 625,000 vehicles.
Some of the cars affected were built by Mitsubishi and supplied to Nissan, which discovered the deception, according to Mitsubishi. It's not yet clear whether the affected cars were all sold in Japan or whether some were exported.
The admission, coming after Volkswagen's deceptive software that hid the true emissions of the company's "clean diesels," is a second black eye for automobile manufacturers.
Mitsubishi Motors President Tetsuro Aikawa and two other executives bowed in apology at a briefing in Tokyo, news agencies reported.
While different from the VW dirty diesel scandal, the Mitsubishi admission further tarnishes automakers' credibility and recalls a 2014 scandal involving Hyundai and Kia, which paid fines and forfeited emissions credits after admitting they had overstated mileage ratings.
Ford also backed off some of its claims for hybrid models in 2013 and 2014.
In the Mitsubishi case, Kyodo reported that Mitsubishi was suspected of manipulating the load placed on the tires of four different models in order to make their fuel economy performance appear better.