McLaren's Lewis Hamilton believes Red Bull can go at least half a second quicker than it was during today's practice for the Malaysian Grand Prix.
Red Bull's Mark Webber topped the times in both the morning and the afternoon sessions, with Jenson Button just 0.005 seconds behind and Hamilton 0.134 seconds off the Australian's best.
But Hamilton, who finished in second place in the season-opening race in Australia, believes Red Bull was still not showing its real pace.
"I think it's a lot of rubbish, really," said Hamilton when asked about comments from Red Bull indicating McLaren was closer in Sepang.
"I'm sure they have another half a second at least to pull out tomorrow. I hope that's the case, that we are closer than we were in the last race, but we'll wait and see tomorrow."
Hamilton was still pleased with his day, although he conceded there was still time to be found.
"I think it's been interesting. Whether it has been good.. We seem to be reasonably close, but I'm sure the Red Bulls will pull something out tomorrow in qualifying. Nonetheless, we found some good things in the set-up of the car.
"Jenson was quite happy in P2. We still have time to find but it's been a productive day, so I can't really complain."
Button was also happy with his day's work, but he admitted he was unsure about how close McLaren was to Red Bull.
"I don't know. We don't know how much fuel they are running, as always. It's a normal Friday comment, I know, but it's the way it always is.
"We just do our own thing and for me the balance improved a lot today, and that's the important thing. The good thing is we found that we made positive steps."