Lewis Hamilton reckons he and Mercedes feel "a little bit lost" with his W15's set-up for the Singapore Grand Prix, after struggling throughout Friday practice.
The Briton only managed to go 12th fastest in FP1 and, despite improving to 11th in the second practice session of the day, he was notably unimpressed with his car's handling traits.
Radio traffic between he and race engineer Pete Bonnington suggested that the seven-time champion was lacking traction out of the slower corners on the Marina Bay circuit, Hamilton feeling that understeer was one of the key mitigating factors.
Speaking after FP2, Hamilton reported that the team had attempted to make a lot of changes to his re-liveried car for the weekend - but nothing seemed to stick.
"This car for me, it feels pretty... it's been a very difficult, very challenging day," Hamilton said of his Friday experience in Singapore.
"We've tried everything set-up-wise, and nothing seems to work with the set-up.
"It's definitely very challenging. We're really giving it everything and then you find out you're a second off.
"I think ultimately we're just a little bit lost at the moment. We're not really sure where to put the car."
Asked if changes between FP1 and FP2 had helped, Hamilton responded: "They didn't do anything, we tried a lot and achieved the same thing.
"At the moment, we won't be going into Q3."
His team-mate George Russell also struggled with his Mercedes' balance.
He suffered a moment during FP2 when he locked up at Turn 8 and ended up going into the wall at low speed. Beyond a broken front wing and crumpled nose, the Mercedes was relatively damage-free.
He noted that the car was feeling "not well connected" compared to previous weekends, but nonetheless targeted the gap between the early pacesetters in Ferrari and McLaren, and the teams behind.
"Not a lot to say [about the crash] really; I locked up, took the front wing off, but it was a really challenging Friday for us," Russell explained.
"We were really off the pace today. We need to understand why that is. I'm sure we'll find some answers tonight.
"We've made some progress from FP1 into FP2. But the car's just not really feeling that well connected as it was this time 12 months ago and in recent races. We need to try and get to the bottom of it.
"There's a lot of surprises out there. You've got the RBs [who are] really quick, you've got the Williams.
"The Red Bulls seem to be off the pace. And there seems to be a big gap to the McLarens and the Ferrari.
"As a minimum, we hope to be in between that midfield gap and the front four. But right now we've got a lot of work on our hands."
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