Daniel Ricciardo says the updated Renault engine has not made much of a difference in terms of power after Friday practice for the Brazilian Grand Prix.
After several delays, Red Bull decided to finally use the new power unit at Interlagos, a move that will mean Ricciardo will be hit with a 10-place grid penalty.
The French car maker has used 11 of the 12 development tokens available to make the engine more competitive.
Although it was already available for the United States Grand Prix, Red Bull has decided to use it in Brazil for the first time.
However, Ricciardo says the engine is still lacking power.
"I am sure the guys will look tonight and see if there are somethings to tune to get more power out of it," said the Australian after practice.
"The positive was it ran all day so we got laps and good information, but the power difference is not so much.
"Williams and Ferrari will show a bit more speed tomorrow. The engine was reliable, sure, but I want a bit more power from it. It's not as much as we would like, but at least we got some good laps and good information."
Ricciardo, finished in the top five in second practice, albeit 1.2 seconds off the pace, and said the goal for the weekend is to maintain that position.
"I think if we can stay top five on this track is good," he said. "I am not sure if we can expect to stay there tomorrow but that is the target, so we will try to do that.
"Today was a smooth day so it's nice to have Fridays like this."