New Audi S4 reduces emissions by a third

Audi unveils the S4 at the Paris Motor Show this week and will seek to demonstrate that equally high priority has been given to thrills and thrift.

The model boasts a new six-cylinder TFSI engine that outperforms its V8 predecessor, but does so with a 30 per cent reduction in CO2 emissions and 29mpg-plus fuel economy. The new S4 and S4 Avant will be available for order in the next few months.

The completely new 3.0-litre V6 shares its 'TFSI' designation with the six engines in the Audi range that combine single turbo charging with FSI direct injection, but the newcomer bucks the trend by using the alternative method of forced induction - a compact supercharger chosen because it delivers a keener response than even two turbo chargers could achieve.

An equally radical departure for the new S quattro flagship is the addition of the S tronic twin-clutch automatic transmission, developed specifically for Audis with longitudinal 'north-south' engine installations, to its options list.

Thanks to advanced electro-hydraulic controls and the alternate use of two clutches, the new seven-speed transmission, which made its debut in the Q5 SUV, delivers a lightning fast manual shift with virtually no interruption of the engine's power delivery.

Making its debut in the S4, the active sport differential enables the quattro system to not only transfer torque between the front and rear axles to counter traction losses, but also between the rear wheels.

S4 buyers can choose from three distinct Audi drive select option packages - Audi drive select with damper control for even greater suspension adaptability to the road surface, Audi drive select with dynamic steering allowing alteration of the actual ratio of the steering for optimum feel, and Audi drive select with upgraded quattro drive featuring the active sport differential. Alternatively, for the ultimate S4 driving experience, all three systems can be combined.

Inside, the 'S' theme is subtly conveyed by sports seats upholstered in leather and Alcantara. The already high specification in the appreciably more spacious cabin can be augmented by options such as a 505-watt Bang & Olufsen audio system, the Audi Music Interface with iPod connectivity, adaptive cruise control, the Audi side assist lane change assistant, the Audi parking system advanced and adaptive light swivelling headlamps for improved corner illumination.