Daniel Ricciardo says watching onboard footage from Formula 1 rivals Ferrari and Mercedes has exposed Red Bull's main weakness as a lack of rear downforce.
After a disappointing Australian Grand Prix, in which Ricciardo and team-mate Max Verstappen were unable to challenge for victory, Red Bull has been working to establish where improvements can be made with its RB13.
But Ricciardo believes video of Ferrari and Mercedes in action around the Albert Park circuit has told him everything he needs to know about where their advantage is.
"At the moment, we don't have enough rear grip - so downforce basically," Ricciardo said in Shanghai on Thursday.
"But to be honest, I don't know if it is we don't have enough or we haven't set the car up in the right way.
"I still feel that we haven't got the most out of the downforce.
"[From] Melbourne, if I watch some onboards of Ferrari or Mercedes, it looks like they have more rear grip than us - so probably we don't have as much as them, period.
"I don't think we have understood it well enough yet to get the most out of it with set-up and ride heights, that sort of thing."
Ricciardo had a troubled home grand prix, with Verstappen Red Bull's top qualifier in fifth but 1.297 seconds slower than polesitter Lewis Hamilton.
Verstappen also finished fifth, 28.827s behind victor Sebastian Vettel, and his fastest race lap was 0.426s slower than the benchmark set by Kimi Raikkonen, who also led pre-season testing at Barcelona.
"For me and probably Max as well, we just felt that looking at Ferrari and Mercedes, we couldn't attack the corner as much because they just seem more planted on the rear," Ricciardo added.
"Even on the high-speed [corners], we can kind of match them, but I feel we are like this [up to our neck].
"There was an onboard from one of Kimi's best laps from testing, and Turn 3 - I think the top teams are doing Turn 3 full [throttle] - he did it, and he didn't even use all the track.
"He didn't let the car run out to the edge so, wow, he has got some downforce.
"I think it is something we knew from early on, that that is an area we have to work on now."