The Spaniard, who moved from Ferrari to Williams over the winter as he was replaced by Lewis Hamilton, put in an impressive 127 laps during his full day of running, but still remains uncertain about how to extract the maximum performance from his new car.

“In terms of driving style, I’m still understanding what I need to do with this car to go quick, because, if I’m honest, I’m still a bit lost as to where to find the lap time,” Sainz told F1TV.

“I don’t know if it’s gonna come on entries, it’s gonna come on exits, minimum speeds.”

His extensive mileage on the second day may have given an encouraging impression, but the 30-year-old was quick to temper expectations, emphasizing that he still has work to do to fully adapt to the FW47.

Despite the uncertainty, Sainz acknowledged the importance of his long stint behind the wheel, as it helped him begin to decipher the car’s characteristics.

“And that’s why [that] run was important for me to understand where the lap time is coming from,” he explained.

“I feel like when I push it, I can get to a decent level, but I still don’t know where the last two tenths of the car are.”

His performance has already sparked excitement in the paddock, with some, even Sainz's former team boss at McLaren Andrea Stella, suggesting that Williams could be a genuine contender for the upper midfield battle.

However, Sainz himself remains focused on the finer details of his adaptation, knowing that his ultimate pace will only reveal itself in the early races of the season.

“This is what I will need to discover during the first five, six races, as I put more soft tyres on the car, to try and understand where this is: where’s the lap time gonna come from in this car.”