We just weren't quick enough - Webber
Mark Webber said Red Bull had been "blown away" at the Chinese Grand Prix after being out-paced by McLaren pair Jenson Button and Lewis Hamilton.
Webber and team-mate Sebastian Vettel started on the front row of the grid but finished eighth and sixth.
And after struggling with the wet conditions, Webber said: "We got blown away, it was a difficult grand prix.
"We weren't quick enough. We know [why the car falters in the wet conditions] and we have to improve it."
As the race became a frenzy of dramatic overtaking, rain storms and two appearances by the safety car, the Red Bull drivers were unable to keep up with their rivals.
Vettel puzzled by Hamilton tactics
McLaren driver Button took the chequered flag after his strategic masterstroke in sticking with his slick tyres early on, which ensured he raced from the front throughout.
The race represented an exact reversal of the Red Bull-McLaren finishing positions from the Malaysian Grand Prix where Vettel led a Red Bull one-two while Hamilton was sixth and Button eighth.
Red Bulls have taken pole in each of the four races so far this season and had again been fastest in the dry qualifying sessions in China.
But the Milton Keynes-based team were unable to take that pace into the grand prix, which was hit by several rainy spells - and have won only one race this season.
"They were difficult, changeable conditions, but they are the same for everyone and the car, our car, is sensitive in these conditions," said Webber.
Team-mate Vettel, who started the day on pole position, added: "I guess that for us to finish sixth in the end could turn out to be quite important for us, but our main competitors finished ahead... so that's not nice.
"It was a very difficult race for us. Both of us struggled quite a lot in certain conditions.
"Once we are in clean air our pace was decent, but you know, it is very on/off in these conditions and it is a lot just to maintain track position.
"We need to understand why we were not able, especially out of the restart, why we were not able to be there straight away. We were lacking a little bit of temperatures in the tyre."
Highlights - Chinese Grand Prix