George Russell found himself having to replace his power unit just before the Hungarian Grand Prix when a crack in the engine caused a water leak during qualifying. The incident forced the Mercedes driver to retire at the end of Q3, prompting the team to fit a fresh unit for the race.
Despite the change, Russell will not incur a grid penalty because the new unit is of the same specification and does not exceed the season limit of four power units per driver. In qualifying Russell managed only a seventh‑place lap, a result that was already disappointing given the team's expectations. However, he will line up sixth on the grid, one spot ahead of his teammate Kimi Antonelli, after the championship leader was handed a three‑place grid drop for exceeding the speed limit in the pit lane.
The water‑pressure loss was detected by the engineers as Russell crossed the finish line of his final flying lap, and the car came to a halt as the coolant system failed. Mercedes traced the leak back to the moment when Russell ran over the exit kerb at Turn 4 on his last attempt. The impact appears to have cracked a component in the cooling circuit, allowing a substantial amount of water to escape.
"We lost water pressure and I had a water leak. When I stopped on track, the car was leaking a load of water," Russell told Sky Sports F1. He added a hopeful note, "Fingers crossed it doesn't affect anything for the race." The swap marks Russell's fourth power unit of the 2026 season, but because it is a like‑for‑like replacement, the driver avoids the usual five‑place penalty that applies when a driver exceeds the allocated number of engines. The move also underscores the growing reliability concerns that have plagued Mercedes this year, affecting both Russell and Antonelli in recent outings.
Both drivers have seen valuable championship points slip away because of engine‑related retirements. Russell, in particular, was left speechless after the Belgian Grand Prix when a software glitch in the power unit robbed him of straight‑line speed, culminating in a race‑ending collision with Lewis Hamilton at Spa‑Francorchamps.
Mercedes have since patched the software issue, and the team is confident the fix will be in place for the Hungarian event. Technical director Simone Resta explained the situation on Friday, noting that the software bug was present in every Mercedes car but impacted George more severely than Kimi.
"The software is the same for all the cars, and it was there in every car, but it affected George more than Kimi," he said. Resta also highlighted the disparity in engine age, pointing out that Kimi had been running a fresher unit, which typically delivers a performance edge over a more heavily used engine.
He added that the balance would shift in upcoming races as Russell receives a newer power unit, potentially narrowing the gap. The qualifying order placed Lando Norris in front, followed by Charles Leclerc, Oscar Piastri, Max Verstappen, Lewis Hamilton, Russell, Antonelli, Isack Hadjar, Arvid Lindblad, and Nico Hulkenberg. Even before the water‑leak incident, Russell had been trailing his teammate throughout the European swing, a trend that has continued into the Hungarian weekend. Starting a place ahead of Antonelli, Russell hopes to chip away at the 50‑point deficit he faces in the drivers' championship.
Yet he remains realistic about the challenges ahead. "We were probably even further on Friday but we had the strongest race pace, which tends to say it's not a car problem but a tyre problem," he remarked. "Time will tell in the race if we struck the right balance between the qualifying setup and race setup.
We probably know we could make the car faster in qualifying trim at the expense of race performance. It's going to be difficult to overtake. It would have been nice to be higher up." The Hungarian Grand Prix schedule is packed with supporting categories: the F3 Feature Race at 7:35 am, Porsche Supercup at 9:05 am, F2 Feature Race at 10:20 am, followed by build‑up coverage from 12:30 pm leading into the main event at 2:00 pm.
The race will be broadcast live on Sky Sports F1 and Sky Sports Main Event, with streaming available via NOW without a long‑term contract. Mercedes will be watching closely to see whether the new power unit and the software fix translate into a competitive performance on the fast, flowing streets of Budapest. The team hopes that eliminating the water‑coolant issue will allow Russell to extract more pace and perhaps secure a better finish than the seventh‑place qualifying result suggests. For now, the British driver must manage tyre wear, balance his setup, and hope that the fresh engine delivers the reliability and power needed to challenge the front‑running cars and mitigate the damage to his championship hopes.