Lewis Hamilton says nothing that Mercedes does to try to improve its Formula 1 car is working in helping it deliver progress it needs to make.
After a tricky opening day of practice at the Australian Grand Prix, Hamilton ended up 13th in the second session – 1.5 seconds adrift of pace-setter Charles Leclerc.
Mercedes is continuing to struggle with porpoising issues on its W13, and its current focus has been on trying to find the right set-up to overcome the problem without it compromising its performance.
However, Hamilton says that Mercedes' trials are not yielding any signs of improvement.
"It's just nothing we change on the car makes a difference at the moment," explained Hamilton after Friday running. "So that's the difficult thing. You're getting very optimistic, and then you make changes, and then it doesn't seem to be wanting to improve.
"We made some changes going into P2. P1 was better. P2 ended up being a bit harder for me. So I don't know, it's just a tricky car."
Hamilton said he was resigned to accepting that the current pace is what he is going to have to deal with over the Australia weekend.
"There's not a lot we can do," he said. "This is the way it is. And so we just have to drive with it. That's the frustrating thing: you're trying to push, you're trying to catch [up] and even when you do a decent lap, it's 1.2 seconds down. So it's difficult."
Mercedes teammate George Russell reckoned that the porpoising he experienced around Melbourne was the worst he had encountered so far this year – but suggested that it may be something he has to live with.
"We're definitely porpoising pretty bad," said Russell, who ended up 11th in the second session. "It's probably the most severe I've experienced, but I think it's something we just have to deal with for the time being as we believe that's the fastest way around the track. But maybe it's not.
"We need to keep digging into the data and understand it. We've sort of gone from left, right and centre with the set-up, and it has all resulted in a similar outcome. So we need to try and get on top of things and understand why."