Toyota is dumping the big V8 engine in the latest redesign of its Tundra full-size pickup truck, a bold move in a market that likes big, powerful engines. The 381 horsepower, 5.7-liter V8 will be replaced by a base 389 horsepower 3.5-liter twin-turbo V6 or an optional gas-electric hybrid system with 437 horsepower. The change is needed because of stronger U.S. fuel economy requirements that soon will be imposed under President Joe Biden, who is scrapping former President Donald Trump’s rollback of the regulations. “Tundra’s new core powertrain offers impressive horsepower and torque that not only improves on the outgoing V8 in terms of performance, but also it’s more efficient,” said Joe Moses, Toyota North America’s general manager for vehicle marketing and communications. The old V8 got only 13 miles per gallon in the city and 17 on the highway. Toyota has not disclosed the estimated mileage for the new …