Paul di Resta revealed he is struggling to work out what went wrong in qualifying after failing to make the cut to progress to Q2 in Hungary.
The Scot will line-up 18th on Sunday's grid after lacking the pace to make it out of the first qualifying segment.
Di Rest could only manage a 1:22.043, which was four-tenths short of what was needed to make it through.
"I can't work it out," he told Sky Sports F1.
"We made some progress ahead of qualifying and went a second quicker than we did on the medium all weekend which I thought was looking very positive. We then put a set of the soft tyres on and only found six tenths instead of the 2.2 seconds that we should find.
"I think everyone within the whole team is confused. We can't work why that should be a big performance delta. It is almost like it is a different compound in tyre. We will have to do something special for tomorrow.
"You have to stay positive. That is by far the worst we have been in qualifying - I know we have had some hiccups, but that genuinely just wasn't there for some reason, but yet we are far better on the other compound. So I think we will just leave that with a big question mark and head into tomorrow as another day."
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