Hyundai is doing as much as it can to turn the page on its 2012 fuel rating issue.

The Korean company announced yesterday that it has entered into an agreement with the U.S. Environmental Protection Agency (EPA) and California Air Resources Board (CARB) to resolve the government’s investigation of its 2012 restatement of fuel economy ratings.

The adjustment affected approximately one-quarter of Hyundai 2011-13 model year vehicles, reducing their combined city/highway fuel economy by 1 or 2 mpg, depending on the model. According to what Hyundai has revealed of the agreement, the company will pay a $56.8 million civil penalty, forgo the use of approximately 2.7 million greenhouse gas (GHG) emission credits – the credits representing the difference between original and restated emission data – and continue to implement a series of measures including the formation of an independent certification test group to oversee the automaker’s fuel economy testing, training, data management and reporting.

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Additionally, Hyundai stated it will continue to audit model year 2015-16 vehicles to confirm the accuracy of their fuel economy ratings.

“Hyundai has acted transparently, reimbursed affected customers and fully cooperated with the EPA throughout the course of its investigation,” said David Zuchowski, president and CEO of Hyundai Motor America. “We are pleased to put this behind us, and gratified that even with our adjusted fuel economy ratings, Hyundai continues to lead the automotive industry in fuel efficiency and environmental performance.”

According to the EPA Fuel Economy Trends Report, Hyundai’s adjusted fuel economy ratings are 27.2 mpg for 2011, 28.3 mpg for 2012 and 29.0 mpg for 2013 model year vehicles.

Hyundai added it believes its process for testing the fuel economy of its vehicles is consistent with government regulations and guidance, which afford broad latitude to vehicle manufacturers in determining test conditions. Outside of a data processing error related to the coastdown testing method by which Hyundai calculated resistance or “road load,” it was Hyundai’s regulatory interpretation within this broad latitude that was responsible for the ratings restatement.

Hyundai explained it has corrected the error, and the EPA in October 2012 approved the automaker’s new fuel economy testing program.

Over the past 30 years, the EPA has acknowledged the variability of its coastdown testing, and currently is working to develop new guidance for the industry in order to improve its precision, repeatability and accuracy.

“Hyundai is committed to partnering with the government to innovate fuel economy testing procedures in order to achieve more accurate and reliable ‘real-world’ results for consumers,” said Zuchowski.

Two years ago, on November 2, 2012, Hyundai announced the voluntary adjustment of fuel economy ratings for approximately one-quarter of its 2011-13 model year vehicles. In order to compensate affected customers, Hyundai provided a lifetime reimbursement program to cover the additional fuel costs associated with the rating change plus a 15 percent premium in acknowledgement of the inconvenience. Hyundai said the majority of customers affected by the ratings restatement enrolled in the automaker’s reimbursement program and are being compensated based on their actual mileage and the fuel costs for the region in which they live.

Hyundai through a recent class action settlement, offered the option of a single lump sum cash payment for those customers who would rather not return to a dealership to have their mileage verified.