The French car manufacturer is evaluating improvements that will help its teams Red Bull and Toro Rosso enjoy a performance boost later on in the campaign.

Part of that push to find more power has involved Renault evaluating on the dyno a single-cylinder prototype provided by Illien's Ilmor company.

Despite initially encouraging results, Renault believes that its own design solutions actually offer a bigger chance of progress.

Renault F1's managing director Cyril Abiteboul said that while he welcomed the help from Illien, his company would not be adopting his design in full.

“I think collaboration is good,” Abiteboul told Motorsport.com. “It is good to work with people outside, because there is no way you can improve inside if you do not put yourself in competition but also in partnership with people that are outside. So first – it is good to get an external look, and support and feedback.

“But right now in our current engine, or the engine that is coming, there is nothing which is coming from Ilmor.

“But that is not to say there won't be anything in the future, or that it has not had a positive influence on what we will be doing at the end of this season.

“On the relationship with Ilmor, I am not saying it has no value. What I am saying is that for the time being, there is nothing proven which will be used in the engine that we will be using.”

Poised for engine token deployment

Motorsport.com reported earlier this month that Renault plans to unleash its remaining engine tokens in one batch later this season when it is convinced it can deliver a good step forward.

Abiteboul said that when his company finally gave the green light for their use, then Renault's teams should expect a proper jump up the grid.

“I want it to be a visible difference, so not just a difference that can be seen with the performance engineer on the laptop looking at the telemetry,” he said. “I want it to be a difference that can be seen in the lap time.

“It is not the type of difference that will allow Red Bull to catch up with Mercedes, let's be frank about that, but it will be a substantial fraction of the deficit we have to Mercedes.”