Mercedes struggles to gauge impact of Sepang upgrade

George Russell was eighth fastest, but both Mercedes drivers will gain a place on the grid because of Isack Hadjar’s engine penalty. The qualifying performance has renewed questions about the substantial aerodynamic update Mercedes brought to a circuit Formula 1 had not visited since 2017.

The team fitted the new package to both cars, leaving it unable to make a direct, like-for-like comparison with the old specification. The answer to whether the upgrade has missed its target is probably no, but its impact remains difficult to isolate. “That is the big question mark,” Russell acknowledged when asked whether it had been hard to unlock the new package’s potential.

The abrasive surface at Sepang has also complicated the assessment: the W17 appears to have struggled particularly badly there. “This circuit is a bit of an outlier in terms of the abrasiveness of the tarmac,” Russell said. He added that lap times seven years earlier were about six or seven seconds faster, and that some sections felt like driving on gravel. In his view, the surface affects everyone, but it is hurting Mercedes more.

Team principal Toto Wolff also stressed how difficult it had been to interpret the car’s behaviour. “We were a little caught out on Friday by some car behaviour we hadn’t seen this year. But it was very hot and the surface is very different from the other circuits,” he said.

The update includes a new floor, with major revisions to its leading edge, the diffuser and the components around the rear wheels. Yet Antonelli and Russell appeared to lose ground to their rivals between final practice and qualifying. Russell finished 0.741 seconds off Verstappen’s pole time, despite the usual two attempts on new tyres in Q3. The result has therefore fuelled questions, without allowing Mercedes to clearly separate the package’s effect from the circuit’s characteristics.