World Champion Lewis Hamilton says he was boosted by set-up changes to his Mercedes W07 Hybrid during the second session for the Chinese Grand Prix after admitting he was initially not comfortable with the car.
Hamilton spun twice in the first session en-route to finishing second to team-mate Nico Rosberg, before placing fourth in the afternoon session.
"It's not been a bad day," said Hamilton, a four-time victor of the Chinese Grand Prix.
"I didn't feel too comfortable with the car this morning but the team made some changes over lunch and it was much better in the second session.
"The weather has been surprisingly warm but with a lot of wind, which made it quite difficult out there through the high-speed corners.
"We're seeing already that tyre degradation will be a big factor this weekend, which is pretty normal for this circuit but definitely something to watch out for on Sunday."
Rosberg, who was third in the second session, is conscious of the threat posed by Ferrari, after the Italian marque completed a 1-2.
"It looks like we are quick here again - but in the afternoon we saw that Ferrari are also very quick, so we are definitely looking out for them and we'll have a bit homework to do tonight," he concluded.