The Environmental Protection Agency found certain 2012–2018 model year GM vehicles were emitting more than 10% higher carbon dioxide on average than first claimed in the company’s compliance reports, the EPA stated. The impacted vehicles include about 4.6 million full-size pickup and sport-utility vehicles and roughly 1.3 million mid-size SUVs, such as Chevrolet Equinox, Tahoe, and Silverado models.

“EPA’s vehicle standards depend on strong oversight to deliver public health benefits in the real world,” EPA Administrator Michael Regan said in the statement. “Our investigation has achieved accountability and upheld an important program that’s reducing air pollution and protecting communities across the country.”

In June 2023, NHTSA said GM paid $128.2 million in fuel economy penalties for not meeting requirements for 2016 and 2017. GM, which sells Chevrolet, Buick, GMC, and Cadillac vehicles in the United States, had not previously paid a fine in the 40-year-old history of the fuel economy program. It had initially planned to use credits to meet its compliance shortfall but opted to pay penalties, NHTSA said.