FSI – The high-tech engine with variable valve lift
The top-of-the-range petrol engine in the Audi A5 is a new 3.2-litre FSI with innovative valve gear comprising the Audi valvelift system. This innovation varies the valve lift between two levels. To achieve this, sets of sliding cams are mounted directly on the intake camshafts. These feature two sets of adjacent cam contours for small and large valve lift. Which cam is used to open the intake valves depends on the power demand at any one time.
The effect is an appreciable increase in engine efficiency. The driver benefits from greater power and improved driveability, while enjoying a marked reduction in fuel consumption. At the wheel of an Audi A5 3.2 FSI there is a whole 195 kW (265 bhp) of power output available and a superb torque of 330 Nm in a broad rev band of 3,000 to 5,000 rpm, ensuring blistering acceleration at all times. Within 6.1 seconds the 3.2 FSI quattro with manual six-speed gearbox sprints from 0 to 100 km/h. The top speed is limited to 250 km/h. Despite this thrilling performance potential the car’s fuel consumption is only 8.7 litres per 100 kilometers (3.2 FSI multitronic).
The all-new high-tech four-cylinder unit in the Audi A5 also does full justice to Audi’s reputation for leading engine technology. The 1.8 TFSI, delivering 125 kW (170 bhp), will be available from autumn 2007. It combines turbocharger technology with petrol direct injection and provides a burst of acceleration and pulling power unrivalled in its class from virtually every rev band. Just as it did with its TDI engines, Audi has accomplished a pioneering feat of engineering with its turbocharged petrol units, taking spark-ignition engines to a new dimension in fuel consumption and driveability.
Thanks to a whole raft of technical innovations in the petrol engines, their fuel economy has been significantly improved, thus yielding a marked reduction in CO2 emissions.
The running gear, precise instruments for agile handling
Even when stationary, the Audi A5 makes a dynamic impression: the wide track, large wheels and short overhangs not only characterise its muscular appearance, they also form part of the formula that produces its peerless active driving feel. The Audi A5 coupé defines the new standard in its class for precise steering response, outstanding directional stability and superb agility, while also offering first-class ride comfort.
The Audi engineers have achieved this with a completely new design of running gear: the front wheels are located by a five-link suspension arrangement with upper and lower wishbones. The wishbones are mounted on a subframe, which is firmly bolted to the body for high rigidity. Another completely reengineered component is the rack and pinion steering. It is located in front of the front axle close to the wheel centre line, and enhances the car’s very agile handling by its direct transmission of the steering forces.
Long wheelbase, short overhang
Overall, the front axle is located a long way forward for a longitudinal engine configuration with front- and four-wheel drive. This new vehicle architecture makes it possible to have a long wheelbase with a short front overhang, and to optimise the axle load distribution. These are all additional elements that enhance the supreme handling qualities of the new Audi A5. To accomplish this special design, the engineers used a trick adopted from the Audi A8: the front axle differential is located in front of the clutch.
A key element of the rear running gear is its trapezoidal-link rear suspension with completely new kinematics. It provides a high degree of ride comfort combined with excellent directional stability. At both the front and rear, the main components of the suspension are made of aluminium. The generous dimensions of the brakes are designed to match the car’s high performance ratings. The braking force can be precisely modulated and the kinematics of the new rear suspension significantly reduce the so-called braking dive effect.
The standard electromechanical parking brake, familiar from the A8 and A6, is activated via a button next to the gear lever. The A5 is also available with the option of Audi hold assist: this ensures that the car cannot accidentally roll back after stopping on a hill.