Mercedes dominated the last day of Formula One testing but most experts left the Circuit de Catalunya with the old suspicion that Red Bull would again be the team to beat when the season begins in Melbourne in two weeks.
Nico Rosberg produced the quickest drive of the winter, knocking almost half a second off the time his new team-mate, Lewis Hamilton, had produced the day before.
Fernando Alonso's Ferrari also beat Hamilton's time, and he was followed by McLaren's Jenson Button and Sauber's Nico Hulkenburg – but they were not as fast as Hamilton had been on Saturday.
Mercedes and Lotus have caught the eye and Ferrari have also looked strong. But there is a strong sense that neither Red Bull nor McLaren have shown their true hands. Rosberg said afterwards: "As we all know we have to be very careful with testing. You just don't know what other people are doing. And we know for a fact that our competitors haven't shown their potential by far. We know that by for sure.
"What I can say is that we've made progress and I'm pleased with the way the winter has gone. Everything has gone to plan. The reliability has been sorted."
According to Rosberg, the strongest point of the car is the balance. "They have got it right and it feels nice to drive. From the first lap onwards this has been a big improvement." He added that the improved aero had also been "one of the key factors".
Of working with his old karting pal Hamilton, Rosberg added: "It's been good. The memories have all come flooding back from when we were together before. It's such a long time ago now – it is like 13 years ago – but it feels like being back then.
"It will be a great challenge for sure. That's what I am here for. He is one of the best drivers in the pit lane but I think we can work well together and push the team forward. That's important."
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image: © Nick Webb