Toto Wolff reveals Mercedes shocking sponsor backlash after signing Kimi Antonelli

Toto Wolff has revealed that two sponsors ended their affiliation with Mercedes over the signing of Kimi Antonelli ahead of the 2025 F1 season.

Antonelli became Formula 1's youngest drivers' champion at the Mexico City Grand Prix, and the boss of the Brackley-based squad was keen to highlight the return on investment the 20-year-old has represented for team partners.

Not only did Antonelli beat Sebastian Vettel's record by over three years, but he also became the first Italian to win the title in 73 years.

Like Jacques Villeneuve and Lewis Hamilton, in 1997 and 2008, respectively, he is just the third driver in F1's modern era to clinch the crown in his second campaign.

Reflecting on the momentous achievement at the Autodromo Hermanos Rodriguez, Wolff shared how quickly he realised the time was right for Antonelli to ascend to F1 once Hamilton opted to leave for Ferrari.

"We have to pinch ourselves because it seems like yesterday he was 11 years old in a garage in junior karting and it goes so fast," Wolff told Sky Sports F1. "He wins the junior formulas, then a difficult year in F2 and that's already where people start outside started to doubt.

"Then when Lewis told me he was going to Ferrari, it was my immediate reaction that we’ve got to put him in the car. But people doubted. We had two sponsors leaving us because of that, because of 'who is this kid?'

"There were others who stayed with us until today. Some are here that reaped the full reward."

Wolff: Antonelli was a 'calculated risk, not a real risk'

Antonelli endured a trying debut season in F1. Although he frequently displayed the pace and potential that earned him the seat alongside team-mate George Russell, he suffered through considerable low points, including his torrid run of results once the paddock reached Europe.

"And then the difficult year and people said again, he shouldn't even be in Formula 1, or he should be at a smaller team," Wolff added. "Over nine races [in Europe], no points, the tears in Spa and then this.

"I'm just so proud for the team that all of them continue to trust him and he delivered."

Expanding on how instantly he knew he wanted Antonelli to graduate to not only F1, but to the works Mercedes team, Wolff insisted it was never an unmitigated risk.

"It was instinctive. Lewis left. I called Bradley [Lord, deputy team principal] and said, 'Kimi is in the car next year'," he explained. "We knew the data, so it kind of felt like the right thing to do. I think it was always a calculated risk, not a real risk."