Bernie Ecclestone says that refuelling could still return to Formula 1 as a way of balancing up car performance, as his plans for an 'alternative' engine ramp up.
The F1 supremo expects the FIA to confirm at the start of next week that it wants to open up a tender for an independent engine supplier from 2017.
As Motorsport.com reported on Friday, a push is being made by Ecclestone and FIA president Jean Todt to introduce an independent supply of V6 twin turbos – most likely to the same 2.2-litre size as IndyCar.
Speaking to media at the Circuit of the Americas on Saturday, Ecclestone said plans for the engine were advanced and confirmation of the FIA's intention was expected imminently.
"The FIA will put out a press release on Monday or Tuesday, I don't know," he said.
Ecclestone suggested that there were already a 'couple' of manufacturer being targeted to win the supply deal, and said he was happy for F1's regulations to be tweaked to ensure both the current and new type of engine were competitive.
"They [the new engine] will probably have more power, and use more fuel," he explained. "So it means I suppose that there will be some regulation changes, which has already been anticipated for 2017, so there is nothing new."
He added: "We used to have people running turbo engine and people running normally aspirated. It wasn't a two-tier system. It was a choice. Whatever it is, I anticipate they will be able to continue running their engine and others running the other engine."
As well as there being a need for the power of the engines to be balanced out, the car regulations may need to be tweaked as well.
Ecclestone suggested that a refuelling option could be put on the table as well, to ensure those cars that ran the less economical engines were not penalised too much.
"Obviously it can be done, yes," he said. "Maybe we will have refuelling again for those that want it. If people have an engine that is super efficient they won't want to obviously. They don't have to."
Refuelling was originally considered for 2017 as a way of making cars quicker in the races, but was rejected after concerns about its impact on the racing.
Ecclestone thinks that he will be able to push the independent engine proposal through the Strategy Group and F1 Commission in spite of manufacturer opposition.
However, there remains the potential obstacle of a long-standing veto that Ferrari has had on technical rule changes
"It depends what their veto rights are. It is a bit complicated actually," he said.
"The funny thing is the Strategy Group is six votes for FIA, six votes for teams and six votes for the commercial rights holder.
"So if by chance, the FIA and CRH agree, it doesn't make a difference what other people do. It is called democracy."
He also dismissed suggestions that car makers would be unhappy at having wasted money on developing the current V6 turbos.
"The money they spent, the R&D they spent, it was for their road cars," he said.
Additional reporting by Adam Cooper