Carlos Sainz, the veteran Formula 1 driver, has recently shed light on his transition from Ferrari to Williams. The switch to a Mercedes power unit, he revealed, has been the most challenging aspect of his move to the Grove-based team.
Sainz, a seasoned driver with 11 seasons under his belt, has represented five other F1 teams before joining Williams. However, this is his first time behind the wheel of a car powered by a Mercedes power unit. The new experience, he says, has been a significant adjustment.
Sainz had his initial encounter with a Williams F1 car during a filming day and a subsequent post-season test at the Yas Marina Circuit in December. Since then, he has driven the FW45 during a two-day TPC programme in Barcelona and also performed a shakedown of the 2025’s FW47 at Silverstone.
Speaking about his first impressions, Sainz said, “The moment there’s a power unit involved, it’s the power unit. The noises, the vibrations, the sound, everything just changes completely.” He further added that understanding the various operations, including the switches, the deployment, the battery, and safety procedures for the engine and the power unit, has been the most significant change for him since joining Williams.
However, despite the challenges, Sainz’s debut with Williams brought some pleasant surprises. His first drive in the FW46, just a day after his second-place finish at the Abu Dhabi Grand Prix, exceeded his expectations.
“First impressions are very important, and that was very positive. I found a car that was honestly a bit better than I thought, or better than I expected, obviously with some deficiencies compared to the cars that I’ve been driving, but not massively far off,” said Sainz at the FW47 launch at Silverstone.
Sainz’s positive assessment of the FW46 was a welcome piece of news for Team Principal James Vowles. He confirmed that having Sainz test with them in Abu Dhabi was invaluable as it allowed the team to identify their weaknesses and confirm that their development was on the right track.
With a move from a race-winning team like Ferrari to a unit that finished ninth in the 2024 Constructors’ standings, Sainz’s expectations for the 2025 season will certainly be different. However, his positive first impressions and vast experience will be significant assets for Williams as they aim to improve their performance in the coming season.