Ricciardo: Renault's spec C engine progress good sign for my future

The Australian will make a shock switch from Red Bull to Renault next year, even though Renault has not yet achieved a podium finish since it return to F1 as a works team in 2016.

But his optimism that the team's progress with its chassis this year can be matched on the power unit front has been lifted on the back of strong gains with the spec C engine that he and Max Verstappen have used since the Italian Grand Prix.

"Through my time with the Renault power unit we've had some updates which have worked and some which haven't," said Ricciardo. "That's been the reality.

"The ones that don't it can be a bit frustrating or demoralising if you're expecting something more than what you're getting.

"Now, this [spec C] 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."

Red Bull boss Christian Horner, who has regularly criticised Renault in the past, also praised the performance step offered by the spec C engine.

Asked by Autosport if there was a noticeable performance step when he ran it in Monza for the first time, Ricciardo added: "There was and to be honest when you hear Christian give it some encouragement, we all know how that relationship is.

"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. 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."

Although the engine had some mapping issues in Singapore, which could make Red Bull switch back to the spec B engine temporarily, Renault's technical chief Marcin Budkowski said he was also upbeat about how the power unit has done so far.

"We are encouraged," he said. "It is the basis for next year's engine.

"There is a lot more hopefully to come for next year's engine, at least that is the plan.

"It is good to have this encouragement and it motivates us to do more of this next year."