Sebastian Vettel says a "draggy car" coupled with a lack of downforce has left Aston Martin stranded in the lower half of the field this season.
The Silverstone-based outfit's maiden F1 season under its prestigious new name has been a disappointing affair, marked by inconsistent performances by its star driver and teammate Lance Stroll.
Like Mercedes, Aston Martin's original low-rake design wasn't helped by the tweak in the aero rules introduced by F1 ahead of the start of the 2021 season.
But while the Brackley squad was able to eventually adapt its car to the changes, and very efficiently at that, Aston Martin's AMR21 has been seemingly stuck in a hole all season long, and showed little progress in the second half of the season, contrary to several of its mid-field rivals.
"We had races where the car felt really good, we had other races where I struggled a lot," Vettel said, quoted by Motorsport.com.
"Overall, what matters is how competitive you are. In competitive terms, I think our car is a bit too draggy.
"We are not having a super-efficient car, plus we don’t have enough downforce. That I think is the main weakness. From there, it’s difficult to overcome that."
Whatever weaknesses which lied under the skin of Aston's charger were compensated for by tyre management and strategy choices.
However, that approach didn't always work in favour of the team's drivers, although it proved productive for Stroll last time out in Qatar where the Canadian clocked in P6 thanks to an impeccably managed one-stop strategy.
"Some tracks helped it [the car], other tracks we overcame it by maybe finding a good set-up and working well on tyres and finding a good strategy," Vettel explained.
"I think overall, when the car is in the window, then we can do a reasonable job and get into points.
"It’s first not always easy to get it into that window, and second, it’s extremely competitive in the area where we race.
"It seems like halfway through the season maybe other teams made a bit more progress than us now."
With the new 2022 season will come a complete technical regulation overhaul, all-new designs and the hope of a reset for teams.
Vettel steered clear of making any bold predictions, but the four-time world champion is nevertheless a believer in Aston's growing engineering potential.
"Obviously, the big unknown is for next year, what’s happening next year with the cars changing and so on, but we will only be able to answer that question next year," said the German.
"But overall, the team I find is strong. In terms of engineering and in terms of trackside, it’s strong. I think it’s growing at pace and lots of plans and good things are coming."