Wolff: Mercedes still need 'crucial' answers about car upgrade

Toto Wolff says it is "crucial" for the development of Mercedes' 2027 car that they understand the full extent of their recent upgrade's potential after a "step in the right direction" at the Singapore Grand Prix.

Mercedes took what Wolff admitted was the "unusual" step of running two different car specifications at the last race after troubles with the big car upgrade introduced onto both W17s at the previous round in Malaysia, the world championship leader's first major upgrade since May.