The engine choice is still a mystery. Some speculate that there will be a twin-turbocharged version of BMW's 4.4-liter V8. However, Robertson has said that Rolls-Royce engines will remain unique to Rolls-Royce, in which case a 12-cylinder motor, unshared with any BMW product and smaller than the Phantom's, has been suggested. And in a nod to green, a diesel option is being floated after the car's introduction.
The car with which the RR4 will compete, Bentley's Continental Flying Spur, has suffered no ill-will for using a VW engine in its Continental series, so perhaps Rolls-Royce will be more welcoming of BMW power when the time comes. The new Rolls is expected to be priced between $250,000 and $300,000, which is considered "entry-level" for this brand.