James Allison says Update 18 aero package hindered Mercedes W17
James Allison revealed that the Update 18 aerodynamic package made the Mercedes W17 difficult to drive and contributed to a shrinking performance gap. While the update increased downforce, it caused unpredictable side effects that prevented the team from maintaining its dominant lead.
Development issues with the W17
James Allison admits the "Update 18" aerodynamic package made the Mercedes W17 a "handful" and contributed to the shrinking performance gap between the Mercedes team and its rivals. The team brought this package to the Sepang track before following it with a new front wing in America. While the update increased downforce, Allison told the NU Silver Arrows Radio Show that the package subtracted performance in areas the team did not expect. These unpredictable side effects prevented the car from delivering a pure step forward in in-lap time. James Allison stated that the car’s driveability suffered late in the year because this development path hindered the machine and prevented the team from maintaining its dominant lead. This flawed aerodynamic package directly impacted the W17 after George Russell and Andrea Kimi Antonelli had initially established a dominant lead to secure both the drivers’ and the constructors’ championships. The field converged as the W17 lost its ability to extract pace.
| Specification | Value |
|---|---|
| FIA minimum chassis weight | 768 kilograms |
| Mandated weight reduction | 30 kilograms |
Weight limits and performance convergence
Mercedes hit the FIA weight targets immediately. The 2026 regulations mandated a 30-kilogram weight reduction for all constructors, which set the minimum chassis weight at 768 kilograms. Mercedes was the only car on the weight limit at the start of the year. Rivals gained lap time advantages as they shed mass throughout the season. Because Mercedes was already "skinny" and on the limit with the weight, they could not access the performance that competitors found by reducing their mass. As rivals lost their excess weight, the field compressed, and the flawed "Update 18" made the W17 significantly harder to extract pace from. Allison noted that competitors had "a bit of timber to shift" to gain lap time. This mass reduction allowed rivals to catch up. The performance gap between the W17 and the rest of the grid has visibly shrunk as the season nears its conclusion, and the W17 is much harder to drive than it was during the opening rounds. The Mercedes advantage disappeared because the team could not improve the car further without compromising its stability.
