The big end of town admits the combustion engine is running on fumes, writes Steve Colquhoun.
Rolls-Royce has joined a growing band of luxury car makers in admitting its gas-guzzling range of cars is unsustainable in the longer term and says it needs a better alternative to ensure it can survive.
It has built a one-off electric vehicle based on its flagship Phantom, which it is showing to customers on a year-long, round-the-world trip to find out what is the most suitable drivetrain to replace its V12-powered range.
The luxury car company isn't the only one trying to wean itself off the planet's rapidly dwindling supply of fossil fuels, however, and rivals from prestige marques BMW and Mercedes-Benz and sports car makers Jaguar and Porsche have all hatched high-end alternatives to traditional large-displacement petrol engines.
Rolls-Royce says it chose a fully electric drivetrain because electric motors can operate silently, adding to the sense of serenity - or ''waftability'', as the company likes to put it - inside the cabin.
Electric drivetrains also typically have an abundance of torque, or pulling power, available from idle to create the sort of effortless acceleration that has previously been obtainable only from large, thirsty engines.
Jaguar announced this year it would put its alternative fuel showcase, the C-X75 concept, into limited production.
It will be powered by a small-capacity turbocharged petrol engine coupled with a pair of electric motors.
That technology is expected to filter throughout the rest of the Jaguar range over time.
Tata Motors chief executive Carl-Peter Forster says Jaguar's off-road sibling, Range Rover, is likely to benefit from the same technology, too, as it tries to change its thirsty reputation.
"In two to three years you'll see the first regular series production hybrids in Range Rover or Jaguar," Forster says. "From there, we'll populate more and more car lines with them."
Porsche has unveiled a petrol-electric hybrid version of its Panamera four-door ''coupe'', although it is trumped for fuel use by a diesel-engined model.
Lexus was a pioneer of hybrid technology with its limousine-size LS range, while BMW and Mercedes-Benz have each hatched petrol-electric versions of their range-topping 7-Series and S-Class models, respectively.
Supercars have also joined the quest, with Audi leading the way with its E-Tron range of all-electric concept cars.
However, Rolls-Royce says its electric car, dubbed the 102EX Experimental Electric, was not motivated by green objectives, frankly admitting its interest in alternative technology is purely a business decision.
''This is not about green technology, this is not a green project, it's about exploring where we go with Rolls-Royce in alternative drivetrains,'' Rolls-Royce Asia-Pacific spokesman Hal Serudin says.
''We believe there is a debate about people who say electric may not be right for Rolls-Royce and some people who say, 'We're fine with it.'
''I'm not at all bothered by the perceived issues of range anxiety, or lack of range. So we're trying to see if there are different sets of customers out there.''
Emily Dungey, the company's spokeswoman for the 102EX project, adds: ''It's more looking at business sustainability. We're very aware as a manufacturer that the automotive industry at large is changing in 50 - or however many - years. We're likely to not be able to have fully petrol cars. So we're looking to gather a rounded strategy for the future into what's suitable for Rolls-Royce.''