McLaren is rolling out a substantial upgrade package for the MCL40 starting at the upcoming Belgian Grand Prix. The team will equip both Lando Norris and Oscar Piastri with the latest Mercedes power unit specification. The factory confirmed the new internal combustion engine and a redesigned rear wing assembly will debut directly during Friday’s practice sessions at Spa. Team Principal Andrea Stella structured the rollout across the Belgium and Hungary double-header to aggressively close the development gap to the factory Mercedes team before the summer shutdown.
The adoption of the new power unit was a highly calculated delay. McLaren opted to maximize the mileage on their existing units after early-season battery failures disrupted their rotation strategy. That waiting game gave them a clear picture of reliability. Factory drivers Kimi Antonelli and George Russell already debuted the hardware at the Austrian Grand Prix, while customer teams Alpine and Williams received the allocation at Silverstone. Now, McLaren gets the turn.
Preparing for Spa requires highly specific aerodynamic and electrical adjustments. Technical Director of Applied Engineering Neil Houldey stated that the team completed extensive simulation runs focused entirely on energy management for the long straights. Houldey expects the circuit to generate a high volume of “super clip” events. That specific phenomenon will severely test the thermal limits of the new power units and the drivers’ energy deployment strategies on track.
But the factory is deliberately staggering the bodywork changes. While the rear wing and engine drop at Spa, the heaviest aerodynamic revisions are not ready yet. The largest aero package will arrive the following week at the Hungarian Grand Prix to target downforce efficiency.
The Verdict
McLaren’s staggered upgrade strategy is a necessary mechanical risk. By waiting to install the proven Mercedes ICE until Spa, Norris and Piastri gain a distinct, fresh power advantage on a highly power-sensitive track. Fans should watch Friday practice closely to see if the new rear wing balances the heavy energy demands Houldey predicted.