Shovlin added that the conditions made things even more tricky to decipher, explaining that the changing wind directions, in particular, made for a difficult read into how the car was behaving and the reasons behind it.
“The wind made it tricky when the wind is behind the car you lose a lot of downforce because effectively the airspeed is reduced. So, some corners were, where the wind was behind, it was prone to doing that.
“Then also the tyres are quite easy to overheat on that circuit. And if you start sliding you tend to lose grip in it and it gets worse. So there’s a few problems now. Importantly, we could see that some of our competitors weren’t struggling in the same way as us.
“So we need to put quite a focus on understanding why the rear end was a bit weak, how we can get it more stable and predictable enough that works going on now.
“Hopefully when we get to the race weekend it won’t be so difficult for the drivers because they were having to work pretty hard to do the lap times that they were doing.”
Mercedes ended testing fifth-quickest on the final day and over a second down on Red Bull’s Max Verstappen who topped the timing sheets.
After the test, Hamilton suggested that the new W12 was lacking across the board rather than in one particular area.