Mercedes technical director James Allison qualified as "promising" the team's start to its Brazilian Grand Prix weekend despite Friday's tricky mixed conditions.
The days' first practice session - conducted mainly in wet conditions - saw only limited running from Lewis Hamilton while Valtteri Bottas concluded FP1 just behind Red Bull pace setter Alex Albon.
However, Hamilton and Bottas topped the mileage chart in the afternoon as the pair worked on the set-up of their W10.
"After a fairly washed out first session it was nice to get the car running in the second session and broadly it was a good day," said Allison.
"The car is reasonably well balanced, and it looks pretty useful on the long-run simulations. We've got a little bit to find in the short runs ahead of qualifying tomorrow, so we've got some work to do overnight.
"We've also got some thinking to do because although it was dry this afternoon, the track and air temperatures are not going to be representative of Sunday. But all in all it's been a promising start to the weekend."
Hamilton was satisfied with the result of his day's work and expected more progress in Saturday's FP3 session.
"The afternoon session was nice and smooth, we started on a good baseline and made a couple of adjustments in the short space of time that we had in that session," commented the Briton.
"We will do more work tonight to refine the car which is going to be quite crucial as we only really have two sessions to get it right for qualifying, so it's compacted a little more and we need to be a little bit more precise with the changes that we make.
"But we started off on the right foot, so we should be ok to progress forward."