Although there had been suggestions that the French car manufacturer would be using its latest Spec-C version as the basis of its 2019 power unit, it has now revealed that a total overhaul is being worked on at its Viry-Chatillon base.

Renault F1 managing director Cyril Abiteboul said that the decision to go for an all-new engine was taken because gains were being limited by the current architecture - something that had come to light with its Spec-C.

“It is a new engine,” Abiteboul told Motorsport.com about the 2019 plans. “One of the reasons for it, and why the Spec-C is not delivering more in terms of performance, is because we are not held back by the structural limitations of the [current] engine.”

Abiteboul said that Renault was pushing hard to make a step forward with its power unit in 2019, but was mindful about balancing the quest for more speed against hurting reliability.

“Given the ambition in terms of power improvement for next year, pretty much all of the engine will be new,” added Abiteboul. “Not only on ERS side, because there is little power and little performance to extract there, but the rest of the ICE will be new.

“That is why we need to be a little bit careful and that is why we need to be extremely drastic and have lots of discipline on planning and milestones to make sure that we are not putting ourselves in a difficult position at the start of the season.”

Renault has been encouraged, however, by the progress it is showing on this front on its dyno – with Abiteboul thinking that the company’s advances in 2018 have been disguised by it being unable to introduce better parts due to the limit of engines components per season.

“We are well advanced on the dyno,” he said. “We have covered lots of mileage on the dyno.

“We had two parts which were a problem this year, the turbocharger and the MGU-K. With the MGU-K, we are running, we have not had any problems so far and we haven’t seen any, either on the dyno or on the track.

“The last spec of turbos seem okay too, but they are not on all cars because of the situation where parts introduced mean a penalty.

“That is what is silly with the current regulations, even if you have a better part you cannot afford to introduce it because of all the penalties and all the sporting consequences. That is crazy.

"You are spending money to improve your parts, you approve it on dyno, it is available it is built, it is there [at the track], and you cannot put it on the car.

“That is crazy. There is really something wrong here. But anyway, that is why – those two issues are addressed.”

Abiteboul explained that the decision to go with an all-new power unit for 2019 was prompted by the belief that all manufacturers are still finding scope for big gains with the V6 turbo hybrids – meaning that no one can afford to sit back and consolidate where they have.

“In my opinion what is paying the most in F1 is stability, stability of the objective, of the vision, of the organisation, of the priorities,” he said. “But at the same time, being brave enough to look at what is not good enough or what is not working.

“That is exactly what I have the responsibility of doing with the rest of the management team. And one thing that strikes me is that we see absolutely no flattening to the engine development curve, and that is amazing."