Honda confirms driveability gap remains after first F1 engine upgrade of 2025

Honda has confirmed that its first ADUO power unit upgrade of the Formula 1 season performed as expected on raw performance metrics at Zandvoort, but chief engineer Shintaro Orihara acknowledged that driveability — the feel and consistency of power delivery through a lap — remains a work in progress ahead of the Italian Grand Prix at Monza.

Orihara told media at Monza that data gathered in the Netherlands had been taken back to Honda’s HRC Sakura facility for dyno testing in the 10 days between races. “We brought back all data to the dyno and we brought back all driver feedback to the dyno,” he said. “They have carried out some testing in HRC Sakura to improve our controls to get better driveability. So the main focus point for this weekend will be to confirm those countermeasures in Monza.”

The upgrade itself, which was focused entirely on the internal combustion engine, cleared the most important initial hurdle. “We have observed a step forward in terms of performance, as expected in our metrics,” Orihara said. “We have confirmed what we saw on the dyno, so that was a positive thing that we found in the Netherlands.”

However, the race weekend at Zandvoort exposed a secondary problem. “We found some things to improve in terms of driveability,” Orihara explained. “We updated our combustion characteristics and prepared the data settings and tools to adapt to these new combustion characteristics to get better driveability — but it was not enough to satisfy the drivers. So that is definitely our improvement point.”

Orihara had already flagged driveability as a concern at Spa-Francorchamps before the Zandvoort upgrade was introduced, meaning Honda entered the Dutch Grand Prix weekend aware that the fix would be incomplete. The issue relates to how consistently and predictably the power unit delivers its output across different phases of a lap — a factor that directly affects how confidently drivers can manage throttle application, particularly on corner exit.

Honda declined to share any specific horsepower figures from the upgrade. Orihara had notably arrived at his Zandvoort media session with a written note explicitly stating he would not discuss power gains or lap-time improvements — a prop he joked he no longer needed at Monza. The driveability work now takes centre stage as the manufacturer looks to give its Aston Martin-powered drivers a more complete package at one of the season’s most power-sensitive circuits.