By David Shepardson WASHINGTON (Reuters) – President Joe Biden’s administration on Friday plans to unveil tougher fuel economy standards for vehicles that would reverse his predecessor Donald Trump’s rollback of U.S. regulations aimed at improving gas mileage and cutting tailpipe pollution, officials said. Transportation Secretary Pete Buttigieg and National Highway Traffic Safety Administration (NHTSA) Deputy Administrator Steven Cliff will make a “major announcement” on fuel economy standards on Friday, the Transportation Department said. It did not offer details of the announcement. NHTSA l…