Reigning World Champion Lewis Hamilton conceded he is “struggling” with Mercedes’ W10 in China but asserted the car has the pace to fight at the front.
Mercedes team-mate Valtteri Bottas narrowly edged Ferrari’s Sebastian Vettel to lead the second practice session, but Hamilton was only a low-key fourth.
Hamilton, victor of the most recent race in Bahrain, finished the session seven-tenths behind Bottas.
“It was quite cold out there, which makes it difficult for the tyres,” he said.
“I was struggling with the car today, so we've got work to do, particularly on my side as Valtteri looked much more comfortable in the car.
“We're going to work hard tonight to find some tweaks and hopefully come back stronger tomorrow; the car has the pace in it to compete at the front, we just need to find the right set-up.
“As we expected, the Ferraris still look quicker on the straights, but overall it's very close between the top cars and I anticipate that it is going to be the same tomorrow.”
Title leader Bottas was keen to play down his pace-setting time.
“The day ended up ok, we made it to the top of the time sheets, but it is always very difficult to find a good balance through an entire lap on this track,” he said.
“We got there step by step and the car was feeling okay in the end, but it's only Friday and it's the next two days that count.
“Ferrari still seem to be quicker than us on the straights, whereas we were better in most corners in FP2.
“We still have room for improvement, but we know the others are going to work hard on their cars as well, so we're going to have to wait and how much we can improve in relation to them.”
