McLaren and Williams will bring the biggest upgrades to the Dutch Grand Prix when Formula 1 resumes its season after the off-season.

Red Bull has made a small change to the engine cover that defines it as track-specific, as well as tweaks to the halo and mirror mounts to improve airflow to the rear of the car, but McLaren is the only one of the top four teams with significant updates. A new front brake scoop, front suspension, underbody lip and rear suspension are all performance developments, while a new rear wing and beam wing developed specifically for Zandvoort improve efficiency.

The Williams upgrade is the team’s first major upgrade of the season and is equally notable, with a new floor covering all aspects of the floor bodywork, edges and fences. Alongside the floor changes there is a subtly updated diffuser, while new sidepod intakes have “unlocked performance improvements across the rest of the car”. The engine cover has been adjusted alongside the sidepods, as has the central air intake, although the main focus of the change there is weight reduction.

Alex Albon’s updated Williams FW46 at the Dutch GP. Andy Hone/Motorsport Images

Alpine has introduced a new front suspension that improves airflow to the rear of the car, while an update to the rear brake duct allows for a more efficient compromise between downforce and drag, while RB has a smaller rear brake duct that is used alongside revised winglets.

The only other new parts being brought to Zandvoort are at Haas, where the focus is on the front end of the car. A new front wing redistributes the aerodynamic load and a revised nose helps to achieve a cleaner central flow. These changes have required corresponding adjustments to both the front suspension and the front corner deflectors.

Ferrari, Mercedes, Aston Martin and Stake have not submitted any upgrades to the FIA.

The story originally appeared on Racer