Big U.S. auto makers are building more fuel-efficient engines for pickup trucks, even as the Trump administration—spurred by the industry’s complaints—moves to relax gas-mileage standards intended to fight emissions.
General Motors Co., Fiat Chrysler Automobiles NV and Ford Motor Co. are betting people want both better gas mileage and raw horsepower from their trucks, the most lucrative category in the auto industry. That is prompting them to innovate.
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