The petrol engine is part of Ford’s low-CO2, high performance EcoBoost range and the use of a turbocharger muffles an engine’s natural sound.
However, Ford engineers have added a ‘sound symposer’ to improve the noise the engine makes and give it a sportier sound.
The sound symposer does not affect the refinement of the engine, which remains quiet at low speeds before delivering the ‘growl’ at high acceleration.
Ford engineer Ralf Heinrichs said: "Engine noise should never become intrusive. Our sound symposer only contributes at high acceleration and even at motorway speeds the engine noise is never intrusive.”
The technology was designed for the Focus ST, a sportier version of the standard Focus. It was also used on the high-performance RS and limited edition RS500 models.
According to Heinrichs: "The 1.6 EcoBoost in new Focus is more moderately tuned but still delivers much more feedback than the current Focus."
The 1.6-litre EcoBoost engine, also available for the C-Max and seven-seat Grand C-Max MPVs as well as the new Mondeo, is built in the UK at Ford’s Bridgend engine plant.
Delivering 148bhp, the engine is capable of a 0-62mph sprint time of 8.6 seconds while delivering CO2 emissions of 139g/km. Fuel economy is equally impressive at 47.1mpg for the smaller of two EcoBoost engines in the Focus range.
Other engines offered with the new Ford Focus include a 1.6-litre diesel bringing CO2 emissions down to just 109g/km – one of the lowest in the family hatchback sector.
The new Ford Focus is expected to arrive in summer 2011 with prices starting from £15,995.