Honda’s upgraded Formula 1 power unit created significant drivability problems for Fernando Alonso and Lance Stroll at Zandvoort, with the engine delivering more power than expected under braking after the introduction of its revised Spec 2 package. The behaviour contributed to a difficult Dutch Grand Prix qualifying session for Aston Martin and highlighted one of the challenges created by Honda’s substantial combustion changes.
The possibility had already been anticipated before the weekend. Whenever significant changes are made to an engine, some of its drivability characteristics can also change. When those modifications involve something as fundamental as the combustion chamber and the way the combustion process itself operates, as is the case with the Honda engine developed through the ADUO and introduced at Zandvoort, the behaviour of the car can inevitably be affected.
Honda F1 engine drivability problem hits Fernando Alonso at Zandvoort
That is exactly what Fernando Alonso experienced during qualifying, where the Spaniard finished 22nd and last after encountering difficulties partly related to the power unit and partly caused by a failure of the active aerodynamics system.
The rear wing failed to open during Q1, costing Alonso several tenths of a second. The scale of the problem becomes clear when comparing his speed with that of Lance Stroll on the start-finish straight, where a driver should be able to take full advantage of the active aerodynamics in its open configuration.
Because of the actuator failure, Alonso travelled through that section as much as 24 km/h slower. That was simply too large a deficit to recover over the course of a single lap.
However, the active-aero malfunction is actually the less concerning of Aston Martin’s problems because it is something that can be repaired ahead of the remainder of the weekend. The more important area requiring attention is drivability, with the Honda power unit not always responding in the way the driver expects during braking and therefore increasing the risk of mistakes.
Fernando Alonso says engine continued pushing under braking
Fernando Alonso ran off the circuit at Turn 1 during SQ1 and reported strong vibrations coming from the engine. Lance Stroll did not fare much better. Although the Canadian finished ahead of both Cadillac cars, he ended the day only 19th and was still two seconds away from the fastest Q1 time on a circuit that is not particularly long.
After qualifying, Alonso explained: “Free practice went more or less well, but in qualifying we had engine problems. The engine drivability was pushing under braking, so sometimes it was difficult to stop the car because the engine was delivering too much power.”
The Spaniard then revealed that a second issue had compounded the power-unit problem.
“And then, apparently, the SLM mode [the low-downforce setting for the 2026 car] didn’t work on my car, so I couldn’t open the rear wing. The combination of those two factors made the laps very complicated. When you brake and the throttle stays open, it is difficult to stop the car.”
Why Honda expected problems after its Spec 2 engine changes
In reality, Honda had already anticipated that this type of problem could emerge. Both on the dyno and during the first on-track test at the Budapest filming day, the updated power unit displayed significantly different drivability characteristics compared with the specification Aston Martin had used at the beginning of the season.
This is a relatively normal consequence of substantial engine development. Altering the combustion process also changes the way the engine responds, and those new characteristics then require further refinement through real-world running on the circuit.
The Spec 2 introduced through the ADUO represents an important change because Honda has substantially modified the combustion of its internal combustion engine. While those developments are intended to move the power unit forward, they also alter the way torque and power are delivered to the driver.
Lance Stroll also struggles with Honda power unit behaviour
Lance Stroll encountered the same characteristics from the new Honda power unit. The Canadian confirmed that Aston Martin had several areas to investigate overnight after a difficult qualifying session.
“We struggled with the drivability and there were other things that didn’t work at their best, so we need to understand why. It’s very windy out there, but it’s the same for everyone. Tonight we’ll analyse everything, look at the data and try to make some improvements for tomorrow.”
The issue itself is not entirely new. Aston Martin had already experienced power-unit response and drivability difficulties during the opening part of the season. Part of that challenge came from the Silverstone team producing its gearbox in-house for the first time, while Honda had also yet to fully optimise the engine’s response.
Lance Stroll’s Monaco accident showed the same type of problem
A concrete example came with Lance Stroll’s accident in Monaco. The Aston Martin driver needed to select a lower gear at the final corner than he had used on previous laps, at which point an unexpected increase in power caused him to lose control of the car and hit the barriers.
The underlying characteristic is that the engine tends to deliver more power than anticipated, particularly during downshifts. If that response is not perfectly calibrated, it can cause significant problems for the driver by disrupting the ideal line under braking and during corner entry.
It is an issue that has also affected Audi to some extent and one that requires time to resolve. With the complexity of the 2026 Formula 1 power units and the interaction between engine response, energy deployment and vehicle behaviour, even an improvement in one area can require substantial recalibration elsewhere.
Honda must redo part of its early-season drivability work
Honda had already accounted for the fact that introducing its new specification would require much of the drivability work completed at the beginning of the season to be revisited.
The updated combustion concept changes how the power unit responds, meaning Honda and Aston Martin now need to refine the calibration so that the engine delivers exactly what Fernando Alonso and Lance Stroll expect when approaching the braking zone, downshifting and turning into a corner.
That creates additional work in the short term, as the Zandvoort difficulties demonstrated, but it is also viewed as a necessary step if Honda is to begin making genuine progress with its 2026 power unit. The task for Aston Martin and Honda is now to retain the benefits of the new specification while making its power delivery predictable enough for the drivers to exploit with confidence.
Leave a Reply