Last Updated on February 5 2025, 10:43 am
First Williams test yields eye-opening results for 2025 with a strong first outing for Sainz – Carlos Sainz has officially begun the transition to the next chapter of his Formula One career with a crucial test at the Circuit de Barcelona-Catalunya, providing an early glimpse of what the Williams FW47 could bring in the 2025 season. His first run in Williams machinery was not just a familiarisation exercise but a thorough evaluation, providing the team with invaluable data.
Driving the 2023-spec car, Sainz wasted no time in delivering his assessment, which Williams engineers described as insightful and immediately applicable. The Spaniard’s initial impressions were positive, with the team noting improvements in high-speed stability – a key area where Williams had struggled in previous seasons.
Stability gains and areas for improvement
Sainz’s experience with top teams such as Ferrari allowed him to make a detailed comparison between his previous machines and the Williams car. One of the most notable observations came from Turn 3, where he felt a marked improvement in the car’s balance compared to previous models. This was largely attributed to aerodynamic refinements and weight reduction.
However, he was quick to point out one area that still needed work: traction in slow corners. Turns 10 and 13 in particular revealed lingering weaknesses in mechanical grip and throttle control. The Williams technical staff took this feedback seriously and immediately incorporated Sainz’s suggestions into their ongoing evaluation process.
To further analyse the data, Sainz, Team Principal James Vowles and Technical Director Dave Warner held an extensive post-test debrief. Together they examined the car’s handling, tyre performance and braking efficiency. Unlike a simple driver’s critique, Sainz’s feedback came with actionable recommendations, reflecting his deep technical understanding and ability to translate track sensations into development insights.
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Adapting quickly and setting competitive times
One of the most striking aspects of the test was how quickly Sainz adapted to the Williams car. In the afternoon session, he switched his focus to qualifying simulations and unconfirmed reports suggested that his lap times were already on a par with last season’s midfield contenders. It was an impressive feat, demonstrating his ability to get the most out of the car in a short space of time.
Throughout the session, Sainz tested different Pirelli compounds – hard, medium and soft – in different conditions. The data gathered was crucial in understanding how the car performs at different grip levels, providing Williams with strategic insights for race weekends.
The session also highlighted the developing partnership between Sainz and Alex Albon. Both drivers worked closely together, exchanging information and refining the car’s set-up. Williams sees this collaboration as a key aspect of its 2025 ambitions, aiming to harness the technical acumen of both drivers for continuous improvement.
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Aerodynamic sensitivity still a concern
Despite the overall optimism, Sainz noted some aerodynamic inconsistencies, particularly in variable wind conditions. In long, fast corners, he noted occasional understeer caused by sudden gusts – a recurring problem that Williams’ engineers will need to address before the start of the season.
“The car has a lot of potential, but there is still work to be done, especially on the race pace,” commented Sainz after the test. “Everyone at Williams is hungry for results and you can see that in the way the team is working.”
To address these issues, Williams engineers are already looking at solutions to improve aerodynamic stability ahead of the official pre-season test in Bahrain. One of the key areas of focus will be refining the FW47’s airflow characteristics to ensure more consistent handling in changing weather conditions.
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Weight reduction and its impact
One of the most promising takeaways from the test was the reduced weight of the FW47 compared to its predecessor. Williams suffered in 2024 with the FW46, which was consistently at least 15kg overweight, costing the team an estimated 0.3 seconds per lap.
While official figures have not been released, insiders suggest the FW47 is significantly lighter, bringing it closer to the minimum weight limit. This has had a direct impact on lap times and the car’s overall responsiveness.
A lighter chassis also improves tyre management and overall efficiency, key factors in a season where small power gains can determine championship positions.
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Reliability and stints
The day concluded with a long-distance simulation to assess the car’s reliability and tyre degradation over extended runs. Encouragingly, lap times remained stable and degradation was within an acceptable range.
Williams engineers will now analyse this data to ensure that any wear-related issues are addressed before the Bahrain test. Reliability remains a crucial factor in Williams’ bid to move up the standings, and early indications are that the team has made progress in this area.
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Sainz’s role in Williams’ 2025 ambitions
Having completed his first test, Sainz has already made a strong impression at Williams. His detailed feedback and technical understanding go beyond mere driving ability and reinforce his value as a development driver. His integration into the team seems seamless and the synergy between him, Albon and the technical staff bodes well for the future.
Williams will now take the next steps in its 2025 preparations, fine-tuning the FW47 based on Sainz’s insights. With further testing on the horizon, the team remains cautiously optimistic about its prospects, hoping to consolidate its place in the ever-competitive midfield.
The coming weeks will reveal whether Williams can capitalise on Sainz’s input and translate it into tangible performance gains. But one thing is clear – his arrival has already injected a new level of precision and determination into the team.
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With over 30 years of experience in Formula 1 as an insider journalist, I have built trusted connections across the paddock, from race engineers and mechanics to senior team figures. At The Judge 13, I and a handful of trusted colleagues share exclusive Formula 1 news, expert analysis and behind-the-scenes stories you will not find in mainstream motorsport media.
