Lewis Hamilton says Ferrari is “improving at a serious rate” and is gaining 0.8s on straights to Mercedes at the Russian Grand Prix.
Mercedes has historically dominated at the Sochi Autodrom but trailed Red Bull and Ferrari during practice on Friday.
Max Verstappen led Charles Leclerc during second practice on Friday afternoon but Mercedes took only third and fourth, with Hamilton trailing Valtteri Bottas.
“It’s been a day of discovery and exploring, it started off not too bad and then it didn’t really improve as with the others,” said Hamilton.
“We are losing eight tenths of a second to the Ferraris on the straights. Nonetheless, we have been improving, but they are improving at a serious rate.
“So we’re just trying to figure out how we can improve the car, but it’s not an easy task.”
Bottas claimed his maiden victory from pole position in 2017 and accepted that Mercedes needs to find more lap time if he is to aim for a repeat.
“Red Bull and Ferrari were a bit too quick today,” he said.
“It felt good, there was no massive balance issues with the car, just maybe struggling a little bit with the overall grip and sliding around.
“But apart from that, it felt good and I had fun, but obviously we need to find some gains if we want to fight for the pole tomorrow.”
