Mercedes boss Toto Wolff said that he was happy with the team's start to pre-season testing.
Valtteri Bottas was second-fastest during the first morning at the Circuit de Barcelona-Catalunya. His time of 1:20.349s was set on the medium compound, after a total of 58 laps.
It put the Finn just over a tenth and a half behind Red Bull's Daniel Ricciardo. That wasn't a worry for Wolff, however, especially given the unseasonably chilly conditions.
"It was a solid start," he told Sky Sports at lunchtime. "It's difficult to judge because it is very cold and everybody just collects data and sees how they get on.
"It's interesting to see there are a couple of cars that have been able to post quick times this morning," he added.
Bottas has now made way for Lewis Hamilton to take over the car after lunch. "We are up for an interesting season," predicted Wolff.
This year's W09 is said to be an evolution of last year's title-winning car. Wolff defended the team's decision to stick with what it knows.
"You need to stick to your concept and follow your own strategy and do what's right," he said. "And that is what we have done.
"We had the quickest car last year I believe," he added. "From the simple record in terms of pole positions and race wins we were very solid.
But Wolff insisted that the team wasn't sitting back and being complacent. He said that he would happy have another season of Mercedes domination - even if the fans wanted a close-fought battle.
"From a fan's perspective, I can absolutely understand that you cheer for the underdog," he said. "You want it to be more variable, you want to have more drivers and teams winning.
"But I am not sitting on the fence. I'm responsible for Mercedes and I want to do well.
"I want to do well for the brand and for our team, and that is why I'm giving it my best go at being successful."
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