McLaren pulls the trigger on MCL39 updates, new diffuser debuts in Jeddah alongside reused components
McLaren arrives in Saudi Arabia as the championship leader in both the Constructors’ and Drivers’ standings. In an effort to extend their lead, the team from Woking has approved a new diffuser aimed at widening the MCL39’s performance window for the Jeddah circuit. Let’s take a look in our analysis and gallery at how Norris and Piastri’s car is evolving for the Saudi Arabian GP.
For round five of the 2025 Formula 1 season, McLaren has rolled out the first upgrade package for the MCL39—the current benchmark car on the grid. With a project that builds on the MCL38, Rob Marshall’s team has fine-tuned vortex extraction underneath the car.
Compared to the “original” version used in the first four races, the updated diffuser features slight changes to the exit edge. While visually subtle, the aerodynamic impact is significant. The redesigned geometry allows for greater expansion capacity, improving airflow efficiency and generating more downforce.
McLaren fights drag in Jeddah
This improved airflow expansion also enhances interaction with components surrounding the diffuser, such as the beam wing and rear wheel area. These neighboring elements actively contribute to downforce generation and have been adjusted to better suit the Saudi street circuit.
Jeddah is a high-speed street circuit with long straights that demand low drag. To tackle this, McLaren has opted for a carry-over of components from the MCL38. The chosen parts include the rear wing, first seen in Brazil 2024, and a low-drag beam wing setup.
Only the lower beam wing element features a relatively long chord and a slope designed to extend the diffuser and increase floor-generated downforce. The upper element is nearly flat, minimizing its aerodynamic impact and drag on the MCL39. This solution is almost essential to mitigate the inherent drag of this new McLaren, whose aero efficiency could be a key limitation.
Read also: F1 | Ferrari’s revised rear wing for Jeddah revealed
Follow us on social media: Telegram – Instagram – Facebook – Twitter