Lewis Hamilton says his Mercedes car "doesn't seem to want to improve", despite the best efforts of his team to extract more performance from it.
The seven-time World Champion placed 13th as the chequered flag fell on FP2 for the Australian Grand Prix, with younger teammate George Russell in 11th.
The Mercedes appears to be close to 1.4 seconds slower than the time-topping Ferrari over a single lap, leaving the team with plenty of work to do before Saturday's qualifying session.
But no matter what the eight-time Constructors' Champions do to try and cure their problems, no progress is being made, according to Hamilton.
Hamilton: Mercedes car doesn't seem to want to improve
Mercedes made changes to Hamilton's car after FP1, a session that saw him place seventh, but they did not have the desired effect.
"It's just, nothing you change on the car makes a difference at the moment, so that's the difficult thing," Hamilton said.
"You're getting very optimistic and then you make changes and it doesn't seem to be wanting to improve.
"We made some changes going into FP2, but FP1 was better. FP2 ended up being a bit harder for me. It's just a tricky car."
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Hamilton downbeat after FP2
Hamilton was visibly downbeat as he addressed the media following his Friday running in Melbourne, adding: "There's not a lot we can do."
Mercedes do have one more practice session to come before qualifying, offering them another hour on track to continue to build their understanding of the W13.
"I don't think it's gonna be tricky to fight our way back, it's just that there's not a lot we can do, this is the way it is – we just have to drive with it," added Hamilton.
"That's the frustrating thing, because you're trying to push, you're trying to catch and, even when you do a decent lap, it's 1.2 seconds down, so it's difficult."
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