The Brackley squad focused on long stints rather than glory runs across the three-day winter test in Bahrain, with George Russell taking second on the final day using softer C4 tyres after he and team-mate Lewis Hamilton had stayed well clear of the top of the leaderboard earlier in the week.
PLUS: Why it's a Red Bull vs Ferrari battle in F1 2024 testing's long run times
Trackside engineering director Andrew Shovlin explained that his team still had "more work to do on a single lap" when F1 returns to Sakhir on Thursday for Bahrain Grand Prix free practice.
"We're still trying to fine-tune the set-up, there will definitely be more to come," Shovlin said in a Mercedes social media debrief.
"Overall we're happy, we definitely made progress. In terms of pace, the long run probably looks like our strength at the moment.
"There's more work to do on a single lap, but we should be in a position to hopefully put in a good showing when we get back on track."
Ever since F1 moved to 2022's all-new regulations, Hamilton and Russell have struggled with the unpredictable and "vicious" behaviour of Mercedes' cars.
Consistent and compliant car handling therefore became a key priority for the W15 project and Mercedes' long-run prowess seems to back up Russell's comments that his car is "no longer a diva".
"It's really encouraging that a lot of the problems that the drivers have been talking about the last 12 and even 24 months with W13 and W14, we seem to have got to grips with," Shovlin added.
While Hamilton was pleased with the team's efforts on the 2024 car, he cautioned that Red Bull will still be "out in the distance" with its bold RB20, which caught the eye in Bahrain with exceptional long runs in the hands of Max Verstappen.
"It's much more enjoyable to drive," Hamilton added. "We still also have time to find, but I think Red Bull clearly are out in the distance. But I think it's a good platform to work from this year."
Watch: Time for the Debrief - F1 2024 Pre Season Testing Day 3 Reaction
