Lewis Hamilton says Mercedes enjoyed one of its most positive days of Formula 1 pre-season testing yet as it continues to evaluate its latest aerodynamic upgrade. 

The reigning world champions introduced a revised aero package for the second week of winter testing in Barcelona in a renewed push for added performance amid its own suggestion that Ferrari is currently the team to beat heading into the 2019 season. 

Mercedes has been working hard to understand its new aero concept and the early signs point towards a step forward, according to five-time world champion Hamilton. 

“Today has been a good day - lots of mileage, which is great for us” said Hamilton. 

“It has probably been one of the most positive days for us, we've really learned quite a lot. 

“We've been able to apply our learnings from the morning to the afternoon, so I'm looking forward to seeing how Valtteri felt, but the car looked like it was in a better place. 

“Our understanding of the W10 is continuously growing so it was definitely a positive day.” 

Bottas racked up 97 laps in the afternoon to take Mercedes’ collective pre-season lap count past the 1000-mark as the German manufacturer continued to set the benchmark in terms of mileage. 

“We got a lot of laps in today which is always good,” Bottas explained. 

“I did a race simulation which was interrupted by the red flag, but it confirmed the progress we've made since last week. 

“We're getting more and more prepared for Melbourne, but there's room for improvement and still a few question marks on where we stand compared to the competition. 

“We're focusing on our performance; the entire team is pushing really hard and keeps improving the car and that's all that matters. 

“We need to maximise the last day of testing as it will be our final chance to try out a few things ahead of Melbourne.” 

Technical director James Allison said Mercedes was able to make progress with the front-graining issues it encountered over a race distance earlier in testing, and revealed the team is set to finally focus on some performance runs on Friday. 

“Today was a very productive day, either side of a trouble-free race distance we did a lot of good investigative work and in the race simulation itself,” he said. 

“Unlike yesterday, where we failed to make the tyres live, we had good tyre behaviour across all three stints. We look forward to tomorrow where we will be investigating the range of tyre compounds and focusing more on single lap pace.”