Daniel Ricciardo believes Red Bull is “not strong anywhere” at the moment on a Formula One track, having lost its advantage around high-speed corners.
While the Renault-powered machine has never been top of the pile in terms of straight-line speed, it has usually made up for it with its superior downforce in corners.
But Ricciardo feels they no longer have that edge.
“We’re by no means the quickest in the fast corners, so we’re not really optimal,” he told Autosport magazine.
“I think last year we lacked power, but we were making it up through some high-speed corners and I think we haven’t gained at least in some areas.
“Unfortunately we don’t have a gain anywhere.
“In some places we’re sort of there or thereabouts but we’re not strong anywhere at the moment.”
The team has struggled with reliability this season, with Ricciardo already on his fourth and final engine allocations for 2015.
The Australian, however, has still managed to claim points in every race – not finishing outside the top 10 in the opening four rounds.
His best result ahead of this weekend’s Monaco Grand Prix is sixth. By this stage last year, he’d already scored a podium and two fourth-placings.
Ricciardo said he was enjoying his new role as team leader, with Sebastian Vettel leaving for Ferrari and replaced by Daniil Kvyat.
“Obviously I try and carry a bit more of the weight on me,” he said.
“Knowing that I have a bit more experience than Daniil and I know the guys a bit better, I’m trying to help out that extra little per cent if I can.
“But if I look back at my approach last year and compare, it’s still the same.
“Maybe the extra feedback I’m giving the guys is natural after an extra year with them.
“The results haven’t been what we wanted but I’m still enjoying the challenge.
“I think when we do get the performance that we want it will be a very nice feeling.”
The 25-year-old is hoping that feeling returns this weekend at a place he knows very well.
Ricciardo now lives in Monaco and says there’s no greater test for an F1 driver than the tight street circuit.
“I know there’s that quote about racing at Monaco being like riding a bicycle around your bathroom,” he said.
“Well, when I was a kid I used to love riding my little bike around inside the house – it was more fun, there were more obstacles and a bit more danger. That really is what this is like.”