On the basis of F1's recent engine proposal for 2021, Renault's Cyril Abiteboul sees no reason to change the sport's current power unit platform.
Formula 1 recently revealed a draft proposition regarding the engine of the future, a less sophisticated and costly version of the current 1.6-liter V6 hybrid unit.
But Abiteboul wants clarification on other aspects of F1's prospective regulations before approving Liberty media's vision of the future.
"What we have been presented with is a new engine," he told Auto Motor und Sport.
"That means a new development, a new project, probably more people, more investment.
"The second problem is that we don't know what Formula 1 will look like in 2021.
"The chassis, the cost reduction measures, how the money distribution changes -- we don't know the whole picture," said the Frenchman.
"We have the engine concept but we can only judge that when the other puzzle pieces are together," Abiteboul added.
F1 sporting manager Ross Brawn, in a bid to strip the current unit of some of its costly and sophisticated technology, recommends dropping the MGU-H hybrid element.
But Abiteboul isn't convinced of the idea, despite the fact that the component has been the root cause of many of Renault's engine failures.
"From today's perspective I have to say I don't like MGU-H," said Abiteboul.
"But by 2020 we will have our problem under control.
"Then it will be cheaper for the manufacturers and the customers, and yet everything will start again at zero with a new engine concept," he added.
"And there will again be manufacturers who will find the right and the wrong solutions, dividing the field into two groups again. Therefore, I see no reason to deviate from the existing concept."
