Writing in Motorsport magazine, Hughes discloses that Mercedes' breakthrough 'innovation is having the turbo's compressor at one end of the engine and the turbine at the other, linked by a long shaft through the vee of the engine'.
The 'trick turbo layout' triggers a series of critical performance benefits. As the air is not travelling through as much pipework, a reduction in turbo lag means less power needs to be be harvested from the car's ERS unit to keep the turbine spooled off throttle. That in turn improves the efficiency of the car, with more power reserved for performance gain and less fuel consequentially used up.
Mercedes' customer teams all have the same advantage. However, because McLaren, Williams and Force India only took delivery of their power units relatively recently, they have had less time to work the layout into their respective car designs.
Hamilton's biggest chance
But for the works outfit, the benefits of the W05's innovative layout has proved multifaceted.
With the compressor further away from the turbine - which is spun by hot exhaust gases - the W05 has a smaller intercooler, meaning Mercedes are running with smaller sidepods which boost aerodynamic performance.
Furthermore, with the compressor in front of the engine, Mercedes have also moved their car's gearbox forward, improving its centre of gravity and therefore, in theory, its handling.
But while Mercedes' rivals are aware of the championship leaders' secret, they are essentially powerless to react. The engines for 2014 are now in lock-down, with February 28 marking the agreed homologation date by which all the teams had to register their design for the new season with the governing body, the FIA.