Global Automakers and the Alliance submitted joint comments to NHTSA on Corporate Average Fuel Economy (CAFE) penalties on October 10, 2017. In this comment, the Alliance and Global Automakers request that NHTSA exercise its authority under the Federal Civil Penalties Inflation Adjustment Act Improvements Act of 2015 to reduce the initial adjustment of the CAFE penalty. Such action is necessary to address factors unique to the CAFE program and is appropriate given the substantial negative economic impacts of the full adjustment and that the social costs of the statutory adjustment outweigh the benefits under all penalty increase scenarios examined.