Toto Wolff admits Mercedes' major upgrades appear to have made the car three to five tenths slower in Malaysia.

Mercedes team principal Toto Wolff expressed confusion after the team's first major upgrade package since May appeared to make their car slower at the Bahrain Grand Prix in Malaysia. Despite bringing new floor, sidepod and diffuser components expected to gain three-tenths of a second, the Silver Arrows looked to have gone backwards by three to five-tenths instead.

Both Kimi Antonelli and George Russell struggled in qualifying at Sepang, with Russell finishing eighth and Antonelli fourth. Wolff described being caught out by unusual car behavior not seen all year, noting the team was losing significant time on the straights compared to Red Bull and suffering from excessive understeer in low-speed corners.

Russell reported the car felt very draggy for the first time this season, while both drivers made mistakes on their qualifying simulations after the upgrade failed to deliver expected performance. The team believes the upgrade works but needs to understand why it has not translated to lap time at the Malaysian venue.