It has powered the vehicles of the rich and famous for two decades as a pinnacle of motor engineering.

But now Bentley is calling time on its gas-guzzling 12-cylinder petrol engine as it embraces the rise of electric cars.

The six-litre beast, which has its cylinders arranged in a “W” formation, is used in about a quarter of cars made by Bentley, offering faster acceleration with a quieter drive for buyers who want the best on the market.

Bentley’s decision to scrap the W12 is driven by a plan to go green which will mean all its vehicles are electric by 2030.

“It’s sad that it’s going as it’s one of the well-regarded engines of our time,” said Jim Saker, a motoring expert and emeritus professor at the University of Loughborough.

“The move towards electric vehicles is forcing people down a particular route.”

Although the W12 is Bentley’s flagship design, the sportier, noisier V8 has long been a more popular option, especially for Bentley owners who drive their own car rather than being chauffeured.

Meanwhile, the hybrid V6, which makes use of a lithium battery to smooth out power demand and increase efficiency, is growing in popularity. The company will end production of the W12 by April next year.

The engine helped lend Bentley models such as the Continental GT a quiet, luxurious power that made them status symbols, Mr Saker said.

Prior to its introduction, most Bentleys since 1959 were driven by V8 engines, with the W12 configuration being introduced under the ownership of Volkswagen. Since its first cars, they have had large engine capacities ranging from three litres to eight litres.

More than 100,000 of the engines have rolled off the production line since it was launched in 2003, starting with the Continental GT. They are hand-built, with each unit taking 6.5 hours. Since the introduction of the engine, it has been tweaked to deliver 37pc more power and 25pc less in emissions.

For the biggest engines, the writing has been on the wall for a while, Mr Saker said.

“It’s an engine which you don’t need now,” he said, with smaller units producing similar acceleration and hybrid engines like that available on Bentley’s Bentayga SUV slashing fuel use, and big engines are increasingly seen as self-indulgent as a consequence.

“Petrol heads will miss it tremendously because it’s been part of the heritage of the company for a while,” Mr Saker added.