Sebastian Vettel says his 2022 Aston Martin F1 car is "a completely different animal" compared to its predecessor, in terms of both driving and set-up.
Vettel clocked in sixth fastest at the end of Thursday's session, having racked up a healthy 74 laps of the Circuit de Catalunya.
But the German driver's best lap was a little over a second slower than the fastest time set by Ferrari pacesetter Charles Leclerc.
"In all honesty, there's still an awful lot to understand," said Vettel.
"It's a completely different animal and it wants to be tamed in a different way. That's driving the car, but that's also operating, in terms of set-up.
"We've tried a couple of things. There are some major challenges, like others are also facing, and problems. So yeah, we need to find solutions.
"There's still a lot to learn for me with a car that wants to be driven in a different way, and I'm playing with driving styles, what I can do.
"Equally we are playing with the car, we are trying to solve some of the problems that we have, the challenges we face, find solutions. So there's still a lot to do."
"Everybody's flat out, there's still a very, very steep and high mountain to climb. I can't say at the minute we're seeing the peak, but I think the challenge is fun, and the belief is there that one day we will reach that peak, hopefully just before the season.
"I think it's going to be a long year anyways, and everybody's probably in the same boat in terms of learning these cars and having certain troubles. But so far, all is good."
By "troubles", Vettel was likely alluding to the "porpoising" phenomenon suffered by almost all 2022 cars which has come about as a result of the ground effects concept on which this year's cars' designs are based.
"Obviously the car likes to be lower to the ground, and that's different to the past, but we've seen other cars bouncing a little bit up and down on the straight. We have one of them," confirmed Vettel.
"We are just in the middle of learning, and at this stage it's hard to say whether we're better off or worse off than the others."
Vettel says that he's been struck by the AMR22's singularities which aren't like anything he's experienced in his 15-year career in F1.
"It's very different," he said. "It's a very different position in the car. It's different what you see, because the wheels are bigger, the fairing on top.
"You get used to that stuff quite quickly. But like I said, the driving is different. And I'm still playing around.
"Obviously, not every lap is exactly the same. So you need to pick your battles. But yeah, overall, it's okay, it's coming along. But where we are, I don't know."
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