Mercedes say they are having to "experiment" to extract more pace from their car after finding themselves lagging behind Ferrari and Red Bull as the opening weekend of the new F1 season began.
The eight-time Constructors' World Champions were slower than both Ferrari and Red Bull cars during FP1 in Bahrain, despite running George Russell on softer tyres than their closest rivals.
AlphaTauri's Pierre Gasly ended the session fastest with a 1:34.193, but Russell's fastest lap was just under half-a-second slower – with the pair both using Soft rubber.
Shovlin: We've got a bit of work to do
Speaking to Sky Sports F1, Mercedes' Trackside Engineering Director, Andrew Shovlin, admitted that the team are learning more every day they run the W13, experimenting in their quest to find the pace to match their rivals.
"In terms of pace, we've got a bit of work to do, and we've carried that on from the test into FP1," said Shovlin.
"We're continuing to do experiments, but certainly on single lap [pace], we were one step softer [with the] tyre than the cars we'd like to compete with doing a similar time. It's pretty evident that there is something to do there.
"We're learning with every day at the moment, and it does feel like we've got ground to catch up, but as long as we keep on with that learning, that's the main thing for us."
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What about Mercedes' porpoising issues?
Put to him that Mercedes appeared to be porpoising less than at last week's test, Shovlin agreed progress has been made, but not as much as their rivals.
"It's a continuation of that experiment we were doing at the end of the test," he said, when asked about how the team are trying to manage the situation.
"We did make some progress and we have been playing around with ride heights a bit in this session, but in terms of pushing and pulling the problem of it, what we need to do is just find some proper car performance, so that's what we'll be talking about [between sessions]."
He added: "I don't think we've got as good a handle on [porpoising] as some of the other teams.
"I think the pace that you're seeing at the moment is very much dominated by how well people have got on top of that problem, maybe more so than the kind of base performance of the car in the wind tunnel."
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