Although noting that Mercedes’ W10 had improved over the course of the two pre-season tests, Valtteri Bottas admits it is by no means “perfect.”
The Finn was in action on the final day of testing, putting the W10 through its paces on Friday morning.
That was a marked improvement on Mercedes previous laps times as the Brackley squad took out fuel and bolted the C5 tyres onto the car.
Bottas is happy with the gains but admits more needs to be done.
“It is better. But if it’s enough, that is the big question mark,” he told the media in Barcelona.
“I definitely feel improvements since last week with the stability of the car, and with the overall downforce of the car.
“But we definitely feel that we haven’t unlocked everything that there is to unlock.
“It’s not the perfect car yet. Definitely we feel the potential is there.
“Maybe it’s another car that has quite a small sweet spot, but once you hit it, it can be very quick.
“We are learning massively every day, I feel like it’s been a good step, every time I get back in the car it gets better.”
The Finn believes last year’s third-placed team Red Bull are up there with Mercedes, but added that Ferrari remain the ones to beat.
“I don’t think the difference between us and them (Red Bull) is massive. But Ferrari is ahead of us.
“I also think the whole field has moved closer together.”