Mercedes will not run its problematic floor first introduced at Spa at any point in the Azerbaijan Grand Prix, as it assesses whether this has caused its post-Belgium victory form dip.
Mercedes entered 2024's recent summer break on the back of three wins in four races – including an on-the-road 1-2 at Spa – but the Belgian victory eventually handed to Lewis Hamilton came after it had chosen not to race its latest floor development, having detected problems with it in that event's opening practice sessions.
At the post-break Dutch GP, where Mercedes struggled for race pace after leading FP2, a planned back-to-back test of the new and old floor specifications was thwarted by the inclement weather at Zandvoort, where Mercedes chose to fit the newer floor ahead of its poor race in any case.
It then completed the back-to-back assessment on Friday at Monza last time out – around Andrea Kimi Antonelli crashing George Russell's car and leaving Mercedes light on spare floors – before again fitting the newer version for the remainder of the weekend.
Russell then managed to outqualify Charles Leclerc's race-winning Ferrari at Monza but did not make an impression in the race after his first corner mistake, while Hamilton did not trouble the leading positions in either qualifying or the race in Italy.
Autosport understands that Mercedes has decided not to run the Spa floor at all in Baku to gain a full weekend of data on how the car – which had upgrades to its diffuser, beam wing, front wing and halo that remain fitted, meaning Mercedes has not reverted to its full pre-Spa Hungarian GP specification – performs without it.
When asked to comment on what he suspected had stopped Mercedes replicating its Spa form ever since – particularly if there were conditions or circumstances in addition to the confusion over the floor that had perhaps played a part – Hamilton replied: "There are lots of question marks on a lot of it.
"I think we're just trying to understand it. It could be a number of things. It could be track-dependent, it could be the upgrade. My gut is telling me it could be the upgrade but it's hard to see the difference between the two.
"But we're going to try this weekend [and] roll back on some of it and see whether or not we can spot it.
"There's a lot of work going on just to analyse it because it gives the team a better direction of where they're going for development, not just for this car but for next year as well."
This will enable it to decide how to adapt the floor or other areas of the W15 going forward, or even drop it altogether, given the team is convinced it is a step forward in terms of adding downforce, albeit it is only a small one.
McLaren made a considerable net gain this year by holding back on a planned floor upgrade it thought would make its car quicker after spotting a problem in its development data that the orange team felt would likely trip it up in a similar way to Mercedes, Aston Martin, Ferrari and Red Bull have all endured this year.
When Autosport put Hamilton's "gut feeling" comment to Russell in Baku on Thursday, he said: "The upgrade wasn't a substantial performance improvement and sometimes you've got to look at things just objectively.
"And we brought a new floor, we dropped in performance, and that was the main thing that that changed.
"We knew the upgrade wasn't kind of going to set the world on fire. It was just sort of another step in the direction that we've been pursuing.
"So, reverting to the pre-Spa iteration of floor, if everything were to be absolutely correct on paper, it's a small delta.
"It's better the devil you know sometimes. We know what that floor offers. We know exactly where the setup needs to be, and sometimes with a new upgrade it takes a number of races to sort of learn and understand.
"So, yeah, maybe made that gut feeling [Hamilton referenced] is correct."
