Lewis Hamilton says there is more potential to extract from his Mercedes Formula 1 car as the team continues to work on solving its recent performance issues at the Brazilian Grand Prix.

Valtteri Bottas headed teammate Hamilton by just 0.003s in a closely-fought second practice session as Mercedes ended Friday’s running on top.

While recently-crowned five-time world champion Hamilton said he could feel a vast improvement in his Mercedes car, he conceded his team still has work to do to fully rectify the problems that led to a sudden performance dip at recent races in Austin and Mexico.

Singapore V4, F1,

“The car felt better than it did in Mexico, but we are still working our way through some issues,” Hamilton said.

“The pace doesn't seem too bad, so we just have to keep working on it and improving it. In FP2, it was quite windy and very gusty through the corners, which meant that the car was actually quite tricky to drive.

“We just need to make sure that we are quick enough in the dry. It's very close between all of us at the front, but I think there's more potential in our car, so we just need to try and squeeze it out.”

Bottas ended up only sixth in opening practice but recovered strongly in the afternoon to set the quickest time of the weekend so far in FP2.

“It was a bit of a mixed day; FP2 was much better than FP1,” Bottas explained.

“The morning was quite difficult, it was easy to make mistakes. I had a few lockups and aborted laps, so it was difficult to build a good rhythm.

“But we really improved the car for the afternoon and I managed to find a rhythm. The pace seemed to be good, but it is a short track, so the margins are small.

“There was not a lot of tyre drop-off today, but we're expecting warmer temperatures, so we will have to wait and see if that might bring about some issues.

“It is very close between the top three teams, so we can't feel satisfied about our results today; we know everyone else is going to be working on their performance overnight, so we will have to keep pushing as well.”

Mercedes technical director James Allison added: “We got the short-run pace good, although we think there's more to come tomorrow.

“The long-run pace was there or thereabouts, but I think that we have work to do overnight - as probably do our competitors - to get the car in a place where it is going to be alright for the hotter track that is coming on Sunday.

“So lots and lots of things for us to think about overnight, just one short one-hour session tomorrow to confirm everything and then we're off to find out whether we've made a good job of it or not.”