Daniel Ricciardo says there is more to come from Red Bull following Friday practice for the Singapore Grand Prix.
The Australian was second fastest in the opening practice session, just 0.049s down on teammate Max Verstappen as Red Bull flexed its muscles on the ultra-soft tyre. But the Milton Keynes-based outfit failed to live up to its pre-race favourites tag in FP2 as Mercedes' Nico Rosberg topped the timing screens by a full 0.3s to Ferrari's Kimi Raikkonen, with Verstappen and Ricciardo third and fourth respectively.
Renault has spent three performance tokens on a power unit upgrade, which has so far only been fitted to Verstappen's car. Ricciardo says while Red Bull has some improvements to make, he remains confident there is time to find heading into qualifying on Saturday.
"We had to work for it today, we can find a few things tonight," Ricciardo said. "I am not discouraged by the pace. Where we are is pretty good considering where I feel we can be with the car.
"There is still a lot more we can get out of it. So if we find that, then we will be looking alright tomorrow. But it is close as predicted -- three teams all there within half a second."
Ricciardo, who claimed a second place finish at last year's race, refused to reveal whether he had been hiding his true pace during second practice after appearing to back out of his final ultra-soft run, having been 0.4s up in the first sector.
"I won't say yes, but, no, we just probably got a little bit too hard into the tyres. The ultra-soft is a funny one. It is so straightforward. You think you have the grip and it goes away.
"So we will look into it. We lost a lot quite a lot in the last sector. I could feel that it was a bit scrappy, but there are probably some things I could improve there. But we can get quite a bit from the set up."