Verstappen was second fastest on the first day of Bahrain testing
Red Bull are "the benchmark" in Formula 1 as pre-season testing begins in earnest in Bahrain, says Mercedes team boss Toto Wolff.
World champion Lando Norris ended the first day of the first of two tests in Bahrain fastest by 0.129 seconds from Red Bull's Max Verstappen.
But Wolff said that he had seen on Mercedes' data that Red Bull's new engine was more effective than those of rivals.
"They are able to deploy far more energy on the straights than everybody else," Wolff said. "You are speaking a second, over consecutive laps.
