Formula 1's chief technical officer Pat Symonds says that the best way forward for the sport's future engine development might lie in two-stroke engines.
That's the same sort of engine used in outboard motors and for small bikes and lawnmowers.
Adopting such technology for motorsport's premier class would not be without controversy, but Symonds is adamant that it's a direction worth considering.
"We need to look at what our future power units will look like," Symonds told an energy efficiency conference at the Motorsport Industry Association this week.
"At F1 this is what we are engaged in at the moment. I’m very keen on it being a two-stroke," he is quoted as saying by Motorsport Week magazine.
"Much more efficient, great sound from the exhaust, and a lot of the problems with the old two-strokes are just not relevant any more," he continued.
"The opposed piston engine is very much coming back, and already in road car form at around 50 per cent efficiency.
"Direct injection, pressure charging, and new ignition systems have all allowed new forms of two-stroke engines to be very efficient and very emission-friendly," he added. "I think there’s a good future for them."
With Formula 1 still utilising petrol-driven internal combustion engines as part of a hybrid power unit, it's the all-electric Formula E championship that has been flying the flag for clean and efficient energy in motorsport in recent years.
But Symonds says that even by retaining combustion engines, F1 could still capture the 'green crown' in coming seasons with its focus on synthetic eco-fuels that combine carbon harvested from the air with hydrogen.
"There’s nothing wrong with electric vehicles, but there are reasons why they are not the solution for everyone," he said.
"The internal combustion engine has a long future," he added. "A future that’s longer than a lot of politicians realise, because politicians are hanging everything on electric vehicles.
"I think there’s a very high chance that there might still be an internal combustion engine," he insisted. "But maybe it’s running on hydrogen."