This proposed rule would correct minor technical errors in the greenhouse gas (GHG) emissions regulations finalized in the 2012 rulemaking establishing standards for model years 2017-2025 light-duty vehicles. First, the current regulations pertaining to how credits from the GHG program's advanced technology incentives are calculated result in auto manufacturers, receiving fewer credits than intended for electric vehicles, plug-in hybrid electric vehicles, fuel cell electric vehicles, and natural gas-fueled vehicles. In a petition letter submitted jointly by the Alliance of Automobile Manufacturers and Global Automakers in June 2016, automakers requested that EPA correct these regulations. Second, the regulations regarding how to calculate certain types of off-cycle credits contain an error, raising implementation concerns for some manufacturers. The rule would correct this error in order to clarify the calculation.