Mercedes have taken a few steps forward during pre-season testing, according to team principal Ross Brawn.
Few people gave the Brackley squad a chance of challenging for top honours this year, but many have changed their tune after the team impressed during testing.
Nico Rosberg posted fastest time during pre-season testing in Barcelona this season while his new team-mate Lewis Hamilton wasn't too far off his pace.
"I am pleased with the progress that the team has made over the last month and the steps forward that have been made with the car," said Brawn.
"We have achieved our objectives for the test programme and the mileage that we have been able to complete has been very satisfying. Lewis has settled into the team extremely well and everyone has enjoyed working with both him and Nico throughout the three tests."
The 2013 season gets underway in less than a fortnight in Melbourne and Brawn insists they are "realistic" about their performances at the Circuit de Catalunya and what to expect in Australia.
"We now have one final week back at the factory to complete our preparations," he said.
"Both drivers will be at the factory this week and, as always, there is a lot of work to do in a short space of time. We're realistic about our performance here and our position once we get to Melbourne, and we look forward to the challenge of a new season ahead."
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