Bernie Collins has helped frame a frustrating question for Mercedes at Sepang: how does a major upgrade that was expected to find three tenths of a second end up looking like a loss of 0.3s, 0.4s or even 0.5s? That is the uncomfortable reality Toto Wolff described after qualifying, where Mercedes came away with Kimi Antonelli in fourth and George Russell in eighth, but still well short of the pace that had been forecast.
The headline result was not a disaster, but it was not the response Mercedes wanted from a package designed to move the car forward. Wolff said the team had been “caught out” on Friday by car behaviour it had not seen all year, and the trouble was broad rather than isolated. The Mercedes boss pointed to a car that looked draggy on the straights, especially against Max Verstappen, while also struggling to rotate in low-speed corners such as Turn 2 because of too much understeer.
That combination matters because it suggests the upgrade did not simply fail to deliver its expected gain; it may have shifted the car into the wrong operating window entirely. Before Sepang qualifying, the simulation picture had been clear enough: the package should have brought around three tenths. Instead, Mercedes found itself outside the top three for the first time this season and, by Wolff’s own assessment, some way back from where it expected to be.
A car that is strong in one phase, weak in another
Antonelli’s reading of the weekend supported that idea. He said the new package changed the window in which the car works best, and that Mercedes is now trying to understand that window rather than assuming the same strengths will appear everywhere. The young driver also made the key split clear: the car has been very strong in high-speed sections, but the low-speed performance has been the weak point.
That is a useful clue, because Sepang is not a simple, one-speed test. The circuit’s hot conditions and different tarmac can expose weaknesses that are less obvious elsewhere, and Mercedes seems to have run into exactly that kind of problem. In Hungary, the team had also been outside the top three in qualifying, so this is not the first time it has been forced to explain a result below its normal standard. But Wolff was clear that this one felt different because the behaviour itself was unfamiliar.
That is why the next step is less about headline disappointment and more about diagnosis. Mercedes is still a championship leader in 2026, but championships are often shaped by how quickly a team can understand a bad weekend as much as by how fast it can celebrate a good one. If the upgrade has made the car more sensitive, more draggy or less balanced in low-speed corners, then the fix matters just as much as the original gain.
For now, the answer to the big question is uncomfortable but straightforward: at Sepang, the upgrade did not work as expected. Mercedes did not find the three tenths it had projected. It found a car that, by its own description, looked slower, more understeery and harder to place in the parts of the lap that decided qualifying.
