The Australian has used the latest Spec C engine since the Italian Grand Prix, and believes it demonstrates the progress being made by the French manufacturer.
“Through my time with the Renault power unit we've had some updates which have worked and some which haven't. That's been the reality,” he explained.
“Obviously the ones that don't, it can be a bit frustrating or demoralizing if you're expecting something more than what you're getting.
“Now, this being their latest step, having positives and actual gains from that, is positive. It's encouraging for the next part of this year but also for my future. It's a nice little positive.”
Ricciardo believes his optimism is well placed, citing comments made by current team boss Christian Horner as proof Renault is moving in the right direction.
Red Bull and Renault have had a fractious relationship in recent years, with the team's top brass typically not shy in criticising its engine supplier.
That Horner spoke favourably of the engine, to Ricciardo, is a strong endorsement of Renault's efforts.
“When you hear Christian give it some encouragement, we all know how that relationship is,” said the 29-year-old.
“He doesn't need to say those things, if you know what I mean, but he did and that's a bit of proof in the pudding that it was a step.
“As a driver you could feel it, especially in qualifying,” Ricciardo added of the performance increase in the latest spec Renault power plant.
“That was the first time I turned everything up on it. It felt like it, let's say, pulled a little harder before the braking. It was a step in the right direction, I'm convinced on that.”
The Australian has just six races left with Red Bull before he joins Renault, the next of which is in Russia this weekend.