Listen to this article 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 …