Carlos Sainz Reveals Biggest Challenge With Williams F1 Switch

Williams driver Carlos Sainz has identified the Mercedes power unit as the biggest adjustment he faces following his 2025 move. Having spent four years with Ferrari, he is well acquainted with the Red team's F1 machinery. With Williams being a Mercedes customer team, Sainz must adapt to the unique characteristics of the Mercedes power unit, including its vibrations and overall feel in the Williams FW47.

The Spaniard explained that in his first outing in a Williams F1 car in the post-season test in Abu Dhabi last year, he had to get familiar with the Mercedes power unit before understanding other mechanical and aerodynamic aspects of the car. Sainz also stressed that the buttons on the steering wheel on modern F1 cars are also something that F1 drivers need to get used to when switching teams. Speaking at the F1 75 season launch, the 30-year-old driver said:

"I can talk a bit about [the post-season test in] Abu Dhabi and how the first laps went.

"Definitely a thing you feel the most when you change teams, the moment there's a power unit [change] involved, is the power unit. The noises, the vibrations, the sound, everything just changes completely.

"So even if I went out of the pits trying to understand the aerodynamics and the tyres and the feeling of the mechanical size of the car on the aero, the only thing I had to adapt for the first few laps was just how different a power unit can be."

He added:

"That's [the power unit] probably the biggest change, also the way the power unit operates, in terms of switches, switch changes.

"Especially nowadays in Formula 1, with so much going on, on our steering wheels and with the deployment of the battery, things like the procedures, safety procedures of the engine and the power unit.

"It's all definitely the biggest change that I'm having to adapt to so far in Williams."

Sainz made way for seven-time world champion Lewis Hamilton at Ferrari, who got his first experience with the SF-23 F1 car during a Testing of Previous Cars session at Ferrari's Fiorano test track last month after he arrived in Maranello. Describing the special feeling of firing up a Ferrari F1 car for the first time, he said:

"I've been waiting such a long time for it, so firing the car up, it's like such a new, uncharted journey, and it's the most exciting thing that's happened to me for as long as I can remember.

"It's nothing like the car that I had before over the last 10, 12, 17 years.

"It's unique, and to feel the vibration of a Ferrari engine for the first time, that's what I think ultimately put the biggest smile on my face.

"I'd always seen all the drivers that have come before me in red and wondered how that would look on me.

"It is a real honour to be able to wear this badge and to wear this suit, so hope I swag it out and make it look good."