Toto Wolff says Mercedes needs to hit the throttle on improving in-race pitstops.
Last time out in Austin, Lewis Hamilton hailed the step forward delivered by the team's new floor - but said Mercedes needs to improve "in other areas too - like pitstops".
Recently, in Qatar, the ever-improving McLaren team broke the all-time record for the fastest Formula 1 pitstop - recorded at an incredible 1.8 seconds.
Mercedes' pitstops, in contrast, are often blowing out to 3.5 seconds.
"We can no longer afford the old approach of first and foremost avoiding bad pitstops," team boss Wolff now concedes.
"The others have gotten so much better that we have reached a turning point. We have to improve significantly in this discipline. We have to understand the science behind it, the processes and upgrade our equipment."
F1 sponsor DHL keeps a record of pitstop times, and currently Mercedes sits as the seventh fastest team at changing tyres out of the ten teams - an average of more than 3 seconds per stop.
The devil, it seems, is in the small details - like the design of the wheel guns and wheel nuts.
"We have to work on both the material and the shape of the affected parts," acknowledged Mercedes team manager Ron Meadows. body check tags ::