The McLaren drivers reckon they will be hard-pressed to get into the top five in this weekend's Hungarian Grand Prix, after struggling in practice today.
Lewis Hamilton was the lead McLaren runner this afternoon, but could only manage sixth and was 1.2sec adrift of pacesetter Sebastian Vettel.
"We're massively down – almost a second – in the middle sector, and then a couple of tenths in the first and last sectors, I think the last sector's almost half a second [deficit]," said Hamilton.
"We are pushing, and we're doing the best job we can. With the package we have, we're getting around the optimum from it. We're just trying to dial-in the setup, but there's only maybe a couple of tenths in it.
"So we've got a lot of work to do and I guess this weekend's just about scoring as many points as we can and hoping that the guys ahead have troubles. We'll just try and edge out as much as we can. I think being in the top five could be tricky this weekend."
His teammate Jenson Button was a further 0.4sec slower in second practice and equally pessimistic.
"It's going to be very tricky," said the world champion. "The Red Bull is just so fast. They did a 1m20.0sec. We didn't get near the low 1m21sec.
"The car doesn't feel so good on the softer tire. On the harder tire, the car feels good. I don't know where that time is. I feel reasonably happy with the balance of the car. There's still more to improve, but we're never going to find a second. We'll do the best that we can with what we have here.
"The guys are all working flat-out to improve this car, as we need to at the moment, and I've got belief in them. If we can get into the top five in qualifying, we should be very happy with that."
Hamilton agreed that the McLaren did not have any obvious problems, but was simply not capable of matching Red Bull's lap times.
"The car is the best I've ever had it around this track, and that's still not good enough," he said. "It feels great around the corners, and then you start to push more to try and close the gap to these guys, and then the car starts to be really on the ragged edge. But I think it's just downforce."