Valtteri Bottas kicked off his day's work with Mercedes after lunch, completing 86 laps through a series of long runs, set-up programmes and tyre analysis.
The Finn insisted the team and himself were still in discovery mode as the W08's potential is gradually unveiled.
"We managed to complete more mileage - more than 80 laps in four hours - which is good," Bottas said.
"We're still focusing on the long runs and doing setup changes and learning about the car, so it was a valuable day."
Echoing Lewis Hamilton's comments after the morning session, Bottas admitted the team was not yet satisfied with the car's status.
"We haven't quite got to the point where we want to be yet. There's always work to do with the car and we're evaluating all the upgrades - what's good and what's not good - and seeing in what areas we still need to improve.
"We're not looking at lap times right now, but we can beat the 1:19.705 we set last week if we want to, it's definitely possible."
Asked to cast an opinion of Mercedes' rivals, Bottas was another driver to note the impressive pace of the cars in red.
"I think Ferrari are looking very good - they seem to be consistent and fast. We shouldn't underestimate them or Red Bull.
"We'll need to keep working hard to be in the best shape possible for Melbourne."
GALLERY: F1 drivers' wives and girlfriends
Keep up to date with all the F1 news via Facebook and Twitter
Full results from Free Practice 1 for the Abu Dhabi Grand Prix at Yas Marina,…
On the eve of Formula 1’s thrilling 2025 title decider in Abu Dhabi, the entire…
As Formula 1 prepares to wave goodbye to its current rule set in Abu Dhabi,…
On the eve of Formula 1’s season finale in Abu Dhabi, drivers set aside championship…
Formula 1's 2025 season hurtles toward its dramatic close this weekend in Yas Marina, with…
In a title showdown charged with tension, numbers, and a hint of intra-team intrigue, Max…