Lewis Hamilton has labelled his Mercedes car a "monster of a diva" due to the challenges of getting the set-up right.
The team have battled to understand the W12 throughout the season, with Hamilton previously suggesting that he felt they had been particularly affected by regulation changes introduced for 2021.
Back in 2017, Mercedes team boss Toto Wolff called the Brackley-based squad's car a "diva" because of the difficulty involved in maximising its performance. Hamilton believes that the 2021 counterpart is perhaps even more challenging.
"This one is a monster of a diva," the seven-time World Champion told the BBC.
"It's been harder to get the car in the right [set-up] window. And when you don't get the car in the right window, you just limit your potential.
"So I'm just not able to maximise my ability through the set-up not being in the right place, and it's been very, very hard to get it into the right place."
Set-up has been perfect "once or twice"
Hamilton was able to set-up the car just as he wanted at the Brazilian Grand Prix, a race that he won after starting from 10th on the grid.
However, the Briton says that this has not happened often during the 2021 season.
"In Brazil, I got the car exactly where I wanted," Hamilton explained. "And that was like literally hitting the nail on the head.
"But we've done that maybe once or twice this year. Most of the time, we're not optimising it."
Happy with performance
Despite the issues with his "diva" car, Hamilton is pleased with how he has performed throughout the year.
"I've generally been very happy with my commitment and my performance," he said.
"I would say I've been more committed than I've ever been. What I've noticed this year is that the car has been very, very hard to set up."
With two races remaining, Hamilton trails title rival Max Verstappen in the World Championship standings by eight points.
Meanwhile Mercedes hold a five-point lead over Red Bull in the Constructors' Championship.
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