Mercedes fixes Russell’s Spa deployment problem ahead of Hungarian GP

Mercedes uncovers software fault behind Russell’s Spa deficit

Mercedes has introduced deployment software modifications ahead of the Hungarian Grand Prix after identifying a problem deep in the code on George Russell’s car during the Belgian Grand Prix.

Russell’s Spa weekend was defined by a lack of straight-line speed compared with team-mate Kimi Antonelli. The deficit cost him several tenths of a second per lap in qualifying because his car ran out of battery power earlier on the run to the final chicane. The reason was not immediately clear, but Mercedes’ subsequent analysis found that an element of the power-unit code was front-loading deployment around the lap.

The algorithms therefore directed extra energy towards the run to Les Combes. Combined with differences in how Russell and Antonelli harvested and used energy through the middle sector, that left Russell short of power for the final run. Toto Wolff said the issue accounted for around half of the deficit to Antonelli, with driving style also contributing.

The problem also shaped Russell’s race. A lack of power after Raidillon on the opening lap allowed the chasing pack to close in and contributed to his contact with Lewis Hamilton at Les Combes. Russell, who retired in the gravel, described the situation over team radio as “unacceptable”.

The latest development follows Mercedes’ explanation of the separate engine and energy issues behind Russell’s Spa struggles, with the team now applying countermeasures to prevent a repeat. Mercedes also expects deployment to be less decisive in Hungary because the circuit layout is more energy-rich.

Why both Mercedes cars lacked power on lap one

Mercedes has also traced the opening-lap problem that affected both Russell and Antonelli. A software error meant neither car harvested as much energy as anticipated on the entry to La Source. Additional battery power was then used on the exit of the hairpin to cover a gap caused by turbo lag, leaving both drivers short of the energy expected for the run down the Kemmel Straight.

Because the regulations restrict how quickly deployment can ramp down, neither driver had the extra power they expected when activating the boost. However, their different approaches through Eau Rouge produced different outcomes.

Russell took the corner flat and became locked into a ramp-down rate that left him at 308km/h (191mph) for a period. Antonelli had lifted after Max Verstappen overtook him, placing his car in a slightly different engine mode with more power available. He reached the ramp-down phase later and carried a higher top speed, enough to draft past Verstappen for the lead.

Mercedes’ Hungarian GP software changes are therefore aimed at two distinct Spa failures: the code issue that compromised Russell’s qualifying deployment and the lap-one harvesting error that affected both cars.