Daniel Ricciardo says the set-up of his Red Bull Formula 1 car has felt "irrelevant" throughout the Russian Grand Prix weekend because of the team's tyre struggles.
For the second year in a row Ricciardo has qualified fifth at the Sochi track, 1.7 seconds off the pace.
Ricciardo was only 0.7s from pole at the previous race in Bahrain, but said the Russian venue was a "bogey" track for Red Bull and so being far behind poleman Sebastian Vettel there was not a surprise.
Asked by Autosport if the car was working well within its limitations, Ricciardo replied: "The bigger thing here is the tyres, getting the tyres to work on a smooth surface.
"We've made some set-up changes throughout the weekend, some bits and pieces. It seems like the set-up is kind of irrelevant here.
"It's like you've just got the car you've got, and it's just how you are going to get tyres going."
Ricciardo joked that "the ultra-soft doesn't feel ultra-soft", and said it was proving "trickier to warm up than the super-soft".
He added: "It just seems a bit more hit and miss. That's more the difficulty.
"The car...it's been OK. This track you always slide a bit on entry, then it grips mid-corner.
"It's more just trying to get those tyres going - it was only Q3 we tried to go [for the] first timed lap and get everything out of it.
"That seemed to work in Q3 but up until then it was hard to get the tyres going on one timed lap."
This year's tyres are approximately 25% wider than before, as part of the rule changes to make the cars faster for 2017.
Ricciardo said Red Bull had only just got on top of the ultra-soft compound last season and the changes for this year had set it back.
"It just seems quite fragile, quite delicate," he said.
"We kind of understood it towards the end of last year but now this year, new tyres and compounds, whatever they've done it's kind of put us back at the beginning.
"It still seems to be an understanding process now. They do seem more sensitive this year."
The two Red Bulls of Ricciardo and Max Verstappen were split in qualifying at Sochi by Felipe Massa's Williams.
Ricciardo said the start would be "more crucial for the story of our race" on Sunday that at previous grands prix.
"It's important to try and not let him get in threat off the start, to maybe try and get a tow off the Mercedes in front and use their drag to pull me into Turn 1 and Turn 2," he said.
"If Felipe was to overtake us, overtaking that car would be more difficult.
"If we're able to stay in front we should be able to hold them off."