Apr.7 (GMM) A secret of Mercedes' 2014 dominance has been compared to the game-changing 'double diffuser' innovation of a few years ago.

It emerged in Bahrain that, beneath the skin of the dominant Mercedes-powered cars in 2014, the new turbo V6 features its turbine and air compressors uniquely packaged at either end of the 'power unit'.

It means that, although McLaren, Williams and Force India are also benefitting from the sleek layout, the works Brackley based team had vast lead-time in designing the aerodynamic concept of the dominant W05 around it.

"We're talking about 2014's double diffuser with the exception that you can't copy it this year," Mark Hughes, a highly respected F1 technical analyst, told the British broadcaster Sky in Bahrain.

"Its impact is maybe not quite as big as active ride (suspension), which was in the order of two seconds per lap, but it's certainly a major technical advantage that they've engineered themselves in for the rest of the season."

Hughes explained that, although the customer Mercedes teams are running precisely the same innovation, it is the works squad that is taking most advantage.

"They gave themselves a big head-start -- it was the chassis team's concept to ask for this from the engine people, and they delivered it.

"The difference (for the customer teams) is that they found out about the detail of the engine when they signed the contract.

"But the works team gave themselves three years to conceive the car around that feature.

"For the (customers), it's presented as a little bit of a surprise, but they're still getting an advantage from the system," he added.