Kimi Antonelli has revealed that Mercedes’ recent upgrades are still not delivering what the team expected, despite him winning the United States Grand Prix.

Antonelli continued his unrelenting charge towards a maiden Formula 1 Drivers’ title in Austin as he converted pole position into a ninth victory of the F1 2026 season.

Kimi Antonelli closes in on title with US GP win

The Italian retained the lead on the opening lap despite starting on the medium tyre, one step harder than the soft compound fitted to the Red Bulls and Ferraris behind.

“I mean, we didn’t have much choice, to be fair,” Antonelli told PlanetF1.com and other accredited media. “We didn’t have any new softs, so the new medium was the only choice we really had, or the hard. But, you know, the medium was not amazing.

“I think today the best tyre was the hard, just because it was the most resilient tyre, and it was quite surprising because in recent races the soft has always been probably the best tyre. So, yeah, it was a good surprise, and luckily it worked for us.”

Mercedes opted not to react to Red Bull triggering an undercut with Max Verstappen on Lap 13, instead waiting until 11 more laps had passed to bring Antonelli in, ceding track position but with the caveat that the Dutchman would have to pit a second time.

Antonelli has admitted there was a point where he was unsure whether Mercedes’ decision to avoid covering Verstappen to stick to a one-stop strategy would prove to be the correct call.

“I was a bit concerned in the beginning, but then we were able to extend, and actually the pace came back with the medium, and we were able to extend without losing too much time,” he explained.

“And, yeah, so then, as you know, after doing the first stint on the medium, we were like, ‘Oh, right, we’re going to go for one-stop.’

“And the hard, to be fair, felt very robust, so I felt pretty confident to go all the way to the end. I just didn’t know how much management was required, but, yeah, it was good, and the car felt very good today.”

More reaction to the United States GP on PlanetF1.com

Antonelli’s latest win represented Mercedes’ first since the team introduced a substantial upgrade package at the Bahrain Grand Prix in Malaysia earlier this month.

Following an underwhelming debut with the revised package in Sepang, the German marque elected to revert Russell’s car to the previous spec in Singapore, while Antonelli, who went on to get a podium that weekend, retained the new components.

But although Russell continued to struggle as he laboured to eighth with the updated parts reattached to his W16 at the Circuit of the Americas, Antonelli believes the upgrades are starting to show their worth, albeit with more lap time still to be unlocked.

When asked whether the upgrades were finally delivering the expected potential, Antonelli replied: “In some places, I would say, still not as much as we expected, but in other places it is delivering very well.

“I think in the high-and medium-speed the car is very strong. The balance is good.

“We’re still struggling a little bit in low speed with front locking, but overall, I feel like the package is finally starting to deliver, and we’re starting to see the results and the improvements from the package.”

Antonelli can seal the championship with ninth place in Mexico this weekend, but he has insisted that his approach at the Autodromo Hermanos Rodriguez won’t change.

“I’m going to approach it with the same mindset, just trying to have as much fun as possible, trying to hopefully fight for another win,” he stressed.

“But, yeah, it would be best to finish on a high, and that’s the goal.

“But, yeah, I’m just going to try to enjoy the rest of the season from now on.”