George Russell is seeking answers following Mercedes' high tyre degradation in the Sao Paulo Grand Prix Sprint - despite a set-up designed to protect the tyres.
Both cars started the 24 lap Interlagos Sprint on the Soft C4 tyres, with fast starts having Russell ahead of Lewis Hamilton in third and fourth.
However, the duo quickly began to bleed time to rivals as the W14 lunched through its tyres, with Hamilton struggling in particular.
Russell would finish fourth with Hamilton seventh as the W14's high downforce set-up to protect the tyres did not work as intended.
Reflecting on the final Sprint, Russell was left lamenting the art of tyre management and nursing the tyres, with no other team seemingly as affected as Mercedes.
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"It was really unexpected, we didn't expect to be fastest and we thought we'd be a couple of tenths behind Max, and maybe have a similar pace to Lando," Russell told media including RacingNews365.
"But we clearly got something wrong, as always it is down to the tyres, it is the story of everyone's season and we need to rectify it.
"We know how sensitive the tyres are to the conditions and it is going to be four or five degrees cooler [for the race], and that might transform everything, so all is not lost yet.
"I guess everybody in the paddock wish they understood it, but it is a bit of a black magic.
"We are the slowest on the straights at the moment, so we are very vulnerable.
"If anyone gets DRS behind us, we knew [getting passed] was going to be case, but that wasn't the reason for our lack of ace.
"If anything, putting on a bit more downforce than everyone else, we were expecting to have less tyre degradation, so we really need to understand what went on."