Lewis Hamilton believes the pre-season testing fortnight for Mercedes have been "positive" and he also thinks the Silver Arrows' changes that have been made have also helped the world champions progress.
Mercedes seemed very reserved in Barcelona, but it was evident that Hamilton and his team-mate Valtteri Bottas were not completely comfortable in the W10 in the first week of testing.
However, the team made alterations to its car and it looked a lot more efficient, but the side only had a go at hot-laps on the final two days in Spain.
Hamilton said earlier last week that Ferrari were quicker than his Mercedes team, but the general feeling around the paddock is that the champions will unleash more from its package in Australia.
"The last couple of days have been very positive," Hamilton said after his final stint in the W10. "It felt like the changes we were making helped us progress and gave us clear feedback of when we were moving in the right or the wrong direction.
"Even so, there is still a lot to do, and we are not there yet. There are lots of areas that we're working on, and we're heading in the right direction."
All will be revealed on the Saturday afternoon (March 16 - Qualifying session) whether or not Mercedes have more to unleash in its power unit.