WASHINGTON (Reuters) -Senate Republicans on Thursday proposed eliminating fines for automakers who fail to meet Corporate Average Fuel Economy rules as part of a wide-ranging tax bill, a boost to Detroit automakers selling gas-powered vehicles. Last year, Chrysler-parent Stellantis paid $190.7 million in civil penalties for failing to meet U.S. fuel economy requirements for 2019 and 2020 after paying nearly $400 million for penalties from 2016 through 2019. GM previously paid $128.2 million in penalties for 2016 and 2017. (Reporting by David Shepardson; editing by Diane Craft)