Renault says that Formula 1's costs are too high for it to justify staying in the sport long term as just an engine supplier.
As talks continue among the French car manufacturer's senior management about its long-term F1 plans – which could result in it having its own team once again – it has become increasingly clear that it will not carry on in only providing engines.
And following talks between Renault chairman Carlos Ghosn and F1 supremo Bernie Ecclestone in Monaco to make clear what the company's situation was, the return on costs has emerged as a key factor.
Renault F1 chief Cyril Abiteboul told Motorsport.com: "The one thing I can say is that in our opinion the engine supplier model does not work with the new engine regulations.
"The level of spend is so high that you don't get enough benefit as a supplier to justify the spend – particularly to catch up with people who have placed the bar so high like Mercedes.
"If Mercedes had not placed the bar so high then perhaps the spend would have been more contained and the whole positioning of engine supplier would make sense.
"But right now the boundaries are so far that we have to spend more. And to spend more there has to be more return including from a marketing perspective."
Red Bull still an option
Renault's current contract with Red Bull and Toro Rosso runs until the end of 2016, and despite some challenging times this year, Abiteboul has not ruled out the partnerships extending.
"In theory we could find that marketing value with Red Bull, which is why I still believe there's a Red Bull future," he said. "However, it is more difficult to find than with the previous engine regulations."
Other options for Renault include a tie-up with Force India, Lotus or Sauber.
Abiteboul said it was important that Ecclestone was informed directly in Monaco about Renault's longer term plans by Ghosn.
"There have been a lot of comments from many people who are not representative of Renault – so it was good to take the opportunity of the annual catch up that is Monaco in the absence of a French GP, to do that with Bernie without any middle man."
V6 rules did not address costs
The move to V6 turbo engines in 2014 was demanded by Renault, which made clear to F1 chiefs that it would likely pull out of the sport if new fuel-efficient power units were not introduced.
But while welcoming the technology, Abiteboul says that the high current costs have dampened Renault's enthusiasm for the new formula.
When asked if the V6 move was right for F1, Abiteboul said: "I think we have to give it a bit more time.
"In theory going to an engine which is more fuel sustainable is a good thing, but maybe we have missed a couple of elements – like containing the costs.
"I am sure if we had contained the costs then the performance bandwidth would have been narrower than it is today, which is an issue."