Sebastian Vettel says Ferrari's new Formula 1 car is "a bit draggy", causing it to trail its rivals for straightline speed through pre-season testing.
Vettel completed his final extended run in the 2020 Ferrari car on Thursday before the start of the season, racking up 144 laps as he set the fastest time of the day.
But Vettel's time was still more than a second slower than the best overall lap of testing, set by Mercedes rival Valtteri Bottas last week.
Ferrari has downplay its chances in the early part of the season throughout testing, saying it is a step behind Mercedes and Red Bull.
The team placed a focus on improving the cornering ability of the new car - something it struggled with last year - but its straightline speed has been compromised as a result.
Asked by Autosport about the car's cornering performance, Vettel explained that while the car had improved in this area, it was now on the back-foot on straightline speed.
"We can feel the car is better, I think sector three feels better," Vettel said.
"We also know that it does come with a trade. We still have some work to do, we are slower than we want down the straights because we are a bit draggy.
"We are aware of that, but the objective was to put more downforce on the car which I think we did.
"Sector three does feel better, but obviously getting out of sector three and down to Turn 1 doesn't feel as good as last year.
"Certainly in the corners is where you feel the difference, and where we improved, but it looks like others are even a bit faster."
Vettel said the decision to favour a car with higher downforce is to aid Ferrari's race performance.
The team took nine pole positions last year, but won only three races.
"We worked very hard over winter, and I think our car is a step forward," said Vettel.
"Currently it does come with some more drag, but we are aware.
"We are pushing as hard as we can to get rid of the drag and make it more efficient. But we also believe that come race day, it gives us an advantage the way it is set up now, so we will see.
"It will be key to develop the car, especially since it seems that we're not the very fastest right now."
Mercedes hinted last week that Ferrari had deliberately run its power unit at a low level - something the team denied - in order to downplay its true pace.
While Vettel conceded it was "hard to compare" the frontrunning teams given their varying testing programmes, he said Ferrari's performance had still done little to wow the F1 paddock.
"If you look at the big teams, then nobody is really trying to do anything fancy," Vettel said.
"Most of the work is done in the background and you don't really see.
"I'm curious to really see where we are in Australia. But for sure, it's not like we leave the very strongest impression right now."