The French car manufacturer delivered a new specification power unit at the Brazilian Grand Prix, but it proved to not be much better than the older version.

Despite having some hope that using all the new components of the update – rather than just the internal combustion element that was run in Interlagos – will yet deliver a step, Renault thinks that things have been not helped by relations with its main team having eased off.

“It is true that recent history and uncertainty with Red Bull have loosened the technical collaboration that there was between our respective teams,” said Renault's F1 managing director Cyril Abiteboul.

“Our dialogue has almost stopped. It was only fair for next year, but maybe where we should have been a bit more careful was that it didn't stop for this year.

"It meant we were not maximising the performance improvement of that engine, because if you change one element of the power unit you need to think of the side effect of all the other elements of the power unit.

“I think there is more to come from the elements than we have seen, and again we are not making use of all the hardware that is now available.

"So there is a slight disappointment but there is more to come and more to explain about that.”

Abu Dhabi rethink

Abiteboul has said that a decision will be made in the build-up to Abu Dhabi about what specification of engine will be used in the season finale.

And he has not ruled out the idea of going back to the older unit if it is felt that the new engine has not delivered.

“We have to look at the aftermath of the Brazil weekend of one engine on one car," he said, "understand where we are, and form some conclusions and some decisions for Abu Dhabi as to whether we continue at the same level, try to push one step further or even if we go one step backwards if it is not satisfactory at this point of time.

"But it is very much in relation to learning for next year.”