Audi A3 Sportback: Engine and Transmission
A six-cylinder engine, FSI petrol direct injection versions, the world's only turbocharged FSI and high-torque TDI engines with high-pressure pump-injector fuel injection, Direct Shift Gearbox DSG with twin clutch, 5 and
6-speed manual gearboxes, an innovative 6-speed tiptronic automatic transmission and quattro permanent four-wheel drive:
Offering a wide range of choice but dedicated throughout to sporting performance – this philosophy characterises the range of engines and transmissions offered for the new Audi A3 Sportback at launch. All engines have a further quality in common: they all undercut the limit values laid down in the EU4 standard.
The range of engines at a glance:
3.2 six-cylinder engine developing 184 kW (250 bhp), 320 Nm
2.0 TFSI developing 147 kW (200 bhp), 280 Nm (new)
2.0 FSI developing 110 kW (150 bhp), 200 Nm
1.6 FSI developing 85 kW (115 bhp), 155 Nm
1.6 developing 75 kW (102 bhp), 148 Nm
2.0 TDI developing 103 kW (140 bhp), 320 Nm
1.9 TDI developing 77 kW (105 bhp), 250 Nm
The petrol engines
The 3.2 six-cylinder engine
The highest-performance engine for this model, and also the top petrol engine for the A3 Sportback: the four-litre V6 engine with a displacement of 3.2 litres.
The six-cylinder engine is particularly suited to a distinctly sporty vehicle such as the Audi A3 Sportback thanks to its outstanding torque and power characteristics.
Its maximum output is 184 kW (250 bhp), and the torque range is particularly impressive, peaking at 320 Nm between 2500 and 3000 rpm.
This is just perfect for powerful pulling at all speeds as well as nimble acceleration – regardless of whether the driver opts for a 6-speed manual gearbox or the new, sporty Direct Shift Gearbox DSG.
The performance figures of the A3 Sportback 3.2 quattro with Direct Shift Gearbox DSG are correspondingly impressive: it accelerates from 0 to 100 km/h in just 6.3 seconds and reaches a top speed of 250 km/h (governed).
Throttle valve actuation is designed for an exceptionally agile, spontaneous engine response to accelerator pedal movements. Indeed, particularly the interaction of the engine with ultra-fast, precise control of the Direct Shift Gearbox DSG creates an entirely new sensation of power and performance on the road.
The DSG transmission control exhibits its particularly sporty character in the active throttle blips during downshifts in the selector lever position S and in the manual gate.
The dual-branch exhaust system both helps to cut emissions and makes a very presentable sound. Audi's acoustics specialists have created a sonorous sound which, without ever becoming excessively assertive, is entirely appropriate to the sporting potential of this power unit.
The A3 Sportback 3.2 is equipped with quattro permanent four-wheel drive as standard.
The 2.0 TFSI
The engine range of the new Audi A3 Sportback marks a double "world first": the 2.0 TFSI is not merely an entirely newly developed engine, but the first ever production engine to combine turbocharging with the FSI concept of petrol direct injection.
This combination has already emphatically demonstrated its potential in the world of motor racing: the Audi R8 models with turbo FSI engines are notching up victory after victory on the circuit and recorded already their fourth triumph at the Le Mans 24 Hours in June 2004.
The term "petrol direct injection" highlights the very revealing feature which distinguishes these engines from conventional petrol engines. In contrast to the manifold injection principle, the fuel is injected directly into the combustion chamber.
The injector, located on the admission side in the cylinder head, is served by a high-pressure pump driven by the camshaft and a pressure reservoir shared by all cylinders - the common rail system. The injector controls the injection time to within thousandths of a second at injection pressures of up to 110 bar. By way of comparison, a manifold injection system operates at a maximum of four bar.
The design of the four-cylinder turbo FSI is based on the 2.0 FSI naturally-aspirated engine, with which it shares key dimensions such as the cylinder spacing of 88 millimetres, as well as having the same cylinder head and crankshaft drive. On the other hand, a great many components have been adapted to reflect the substantially higher operating pressures and also the higher dynamic load of the turbo engine.
The engine block is made from GG 25 grey cast iron, a material that exhibits both high pressure resistance and excellent acoustic properties.
A mass balance transmission further improves the acoustics. Two balancing shafts rotating at double the speed of the crankshaft compensate for the engine's inertial forces. The power is transmitted by the crankshaft by means of a triangular-layout chain which drives the oil pump as well as the balancing shafts.
The outcome of these measures is outstanding vibrational properties for a four-cylinder engine. Perceptible vibration and drumming frequencies under load are both effectively suppressed. The pleasing sound of the specially tuned exhaust system aptly complements these properties.
The intake manifold on the 2.0 TFSI is made from a high-tech plastic. It also integrates the charge movement flaps, the position of which is adjusted by a continuous-action pilot motor. The optimum movement of the airflow, or tumble, can thus be controlled on the basis of the engine-speed and load conditions.
The fuel is injected via a common rail system supplied by a demand-controlled high-pressure pump. The fuel is injected directly into the combustion chamber via an injector positioned at one side between the inlet valves.
In contrast to the naturally-aspirated 2.0 FSI engine, the fuel-air mixture is distributed purely homogeneously within the combustion chamber. This provides a distinctive characteristic placing the emphasis on high performance and agile responsiveness at all engine speeds.
The four-valve cylinder head with low-friction roller cam follower drive has a modified inlet duct geometry that produces even higher tumble values than the naturally-aspirated FSI engine. This results not only in greater refinement, but also in superior knock resistance and therefore efficiency.
The result is that the turbo engine achieves a compression ratio of 10.5:1, a figure that is otherwise achieved only by modern naturally-aspirated engines. This, coupled with the advantages of petrol direct injection, plays a crucial role in boosting the thermodynamic efficiency compared with both manifold injection engines and conventional turbo engines: whereas the swept volume in the Audi A3 is just 10 percent higher than that of the predecessor version, the 1.8 T, the torque has risen by all of 20 percent to 280 Nm.
This figure is available from as little as 1800 rpm, all the way up to 5000 rpm. This exceptionally broad torque plateau on the one hand permits a fuel-efficient driving style with few gearshifts, and on the other hand means that only light accelerator action is needed to produce assertive thrust and a spontaneous unleashing of power.
This technology lends the A3 Sportback 2.0 TFSI flexibility values that are on a par with much larger-capacity sports cars: in 4th gear, the mid-range spurt from 60 to 120 km/h that is typically required for overtaking manoeuvres takes just
5.4 seconds. The predecessor accomplished this in 6.8 seconds, thus taking around 20 percent longer.
It is moreover impressive how spontaneously the new turbo engine always responds to accelerator action, and how assertively it translates pedal movement into acceleration. This too can be expressed in figures. Immediately after the throttle has been opened, the 2.0 TFSI summons up around 15 percent more basic engine torque than the 1.8 T, and torque rises to its maximum value much more rapidly: the new turbo FSI reaches the predecessor's peak torque in just half the time – and then goes a significant step further in reaching the maximum value of 280 Newton-metres.
The A3 Sportback 2.0 TFSI with DSG gearbox accomplishes the classic 0-100 km/h sprint in only 7.0 seconds; its powerful 147 kW (200 bhp) engine is capable of taking it up to a top speed of 236 km/h.
The new engine's efficiency is reflected by its remarkably low fuel consumption, for all its high performance. Its average consumption over 100 kilometres is just 7.7 litres of premium-grade petrol.
The Audi A3 Sportback 2.0 TFSI is available both with front-wheel drive and the sporty Direct Shift Gearbox DSG, and with quattro drive and a manual 6-speed gearbox.
The 2.0 FSI
The two-litre naturally-aspirated engine likewise has petrol direct injection: a common-rail fuel injection system and a single-piston high-pressure injection pump supply the engine with fuel.
The four valves per cylinder are actuated by low-friction roller cam followers. The intake camshaft can be continuously adjusted. The 2.0 FSI in the Sportback develops 110 kW (150 bhp) and maximum torque of 200 Nm at 3500 rpm. With this kind of power, the Sportback 2.0 FSI with six-speed manual gearbox accelerates from 0-100 km/h in just 9.1 seconds and has a top speed of 214 km/h.
But its noteworthy efficiency is just as typical of an FSI engine as its sportiness. Because in view of the performance figures achieved, an average consumption of just 6.9 litres of Super Plus petrol per 100 kilometres (overall) is more than impressive.
Thanks to a variable intake manifold and dual-branch front pipe, its torque curve sets standards in this class. This progress has been made possible by the air-guided combustion process of the 2.0 FSI engine. It allows stratified and homogeneous lean operation with excess air at part load.
During stratified-charge operation, the FSI engine's most economical mode, fuel is not injected until the compression phase, and is then transported to the spark plug by the air turbulence produced in the combustion chamber. This causes an ignitable mixture to form around the spark plug, with a substantial air surplus in the remainder of the combustion chamber.
At full load and at high part loads, this FSI engine also operates in the homogeneous mode.
The A3 Sportback 2.0 FSI is available in combination with a 6-speed manual gearbox and with 6-speed tiptronic.
The 1.6 FSI
The third version of four-cylinder engine with FSI petrol direct injection, developing 85 kW (115 bhp) and 155 Nm torque, makes the A3 Sportback 1.6 FSI an economical sprinter.
This propels the dynamic five-door model up to a top speed of 196 km/h; the speedometer needle hits 100 km/h after 11.1 seconds. But this four-cylinder engine has more than just sporting talents to recommend it.
The 1.6-litre FSI engine also demonstrates potential for fuel economy thanks to its petrol direct injection technology. The A3 1.6 FSI consumes just 6.5 litres of Super Plus fuel per 100 kilometres, pushing the figure down to a remarkable 5.3 litres per 100 km in extra-urban conditions.
This is undoubtedly an unbeatably low figure for a petrol engine, considering its performance. The 55-litre fuel tank means that a range of considerably more than 800 kilometres is possible without pauses for refuelling.
One special feature of FSI technology is to be found at the admission end – the tumble flap. This can be adjusted to two different positions on the 1.6 FSI engine, thus specifically influencing the movement of the incoming air.
This paves the way for two different operating modes as the very basis of the FSI principle's versatility: homogeneous-charge and stratified-charge operation. Depending on the engine speed, load status and accelerator pedal position, the engine electronics always select the optimum mode – without the driver even noticing.
The 1.6
The entry-level engine for the A3 Sportback is the well-established 1.6-litre four-cylinder power unit with variable intake manifold and overhead camshaft. With its engine block made of aluminium, this power unit is at least 13 kilograms lighter than a grey cast-iron engine of the same size.
The valve operation by means of roller cam followers results in particularly low internal friction. The other engine components are also optimised for minimum friction in the interest of enhanced fuel economy.
The result is that in conjunction with the 1.6-litre engine and 5-speed manual gearbox, the Audi A3 Sportback uses only 7.1 litres of premium-grade fuel per 100 kilometres (overall).
For all its economy, the A3 Sportback 1.6 is decidedly nimble. Thanks to an engine output of 75 kW (102 bhp) and a torque of 148 Newton-metres, with the
5-speed gearbox it accelerates to 100 km/h in 12.2 seconds and achieves a top speed of 185 km/h. Its responsiveness and acoustic refinement are further arguments in favour of this ultramodern drive version: an ideal basis for the Audi A3 Sportback.
The A3 Sportback 1.6 is initially available in combination with a 6-speed tiptronic, with a 5-speed manual gearbox to follow shortly afterwards.
The TDI engines
The 1.9-litre TDI
One of Audi's most successful and popular engines is also to be found in the A3 Sportback: the four-cylinder 1.9-litre TDI with pump-injector direct injection. The latest version develops 77 kW (105 bhp) and produces an impressive 250 Newton-metres of torque at just 1900 rpm.
The A3 1.9 TDI takes just 11.7 seconds to accelerate to 100 km/h. And with a top speed of 187 km/h, the entry-level TDI model is the ideal car for long stretches on the motorway at high average speeds. Especially as the fuel consumption of around only 5.1 litres per 100 kilometres means that a distance of over 1,000 kilometres can be covered between stops for refuelling.
This once again demonstrates the superior maturity and efficiency of TDI technology in conjunction with the pump-injector unit. Indeed, this system is still able to provide the highest level of injection pressure of up to 2,050 bar – the weight of a car on an area as small as a fingernail.
This high pressure assures ultra-fine atomisation of fuel within the combustion chamber, thus providing excellent thermodynamic efficiency. On the road this means outstanding fuel economy and, at the same time, a high torque yield. And thanks to pilot-injection control, the performance spectrum of a pump-injector engine includes good engine acoustics and efficient emissions control. This likewise applies to the 1.9 TDI, which easily undercuts the EU4 emission limits.
The A3 Sportback 1.9 TDI comes in combination with a five-speed manual gearbox.
The 2.0 TDI
There can be no doubt about it: the 2.0-litre TDI which Audi is also offering for its A3 Sportback has all the virtues of its smaller brother – high power output, superior fuel efficiency and low emissions.
Being the first TDI with a four-valve cylinder head, however, this new engine offers an even better interpretation of these qualities. Maximum output of 103 kW (140 bhp) and peak torque of 320 Nm available all the way between 1750 and 2500 rpm make this the most powerful and dynamic four-cylinder diesel featured by Audi so far. Performance on the road is correspondingly impressive, the front-wheel-drive 2.0 TDI with DSG accelerating to 100 km/h in just 9.2 seconds and continuing up quickly to its top speed of 207 km/h.
Two other key strengths of the new 2.0 TDI are low fuel consumption – 5.5 litres of diesel fuel per 100 km (overall value) – as well as compliance with the EU4 emission standard.
In terms of design, the new power unit is distinguished from its related 1.9-litre version not only by its larger capacity, but above all by the new cylinder head with four valves per cylinder. The crossflow cylinder head with two tangential intake ducts on either side and a twisted valve star assures an optimum combination of swirl and cylinder charge.
Two overhead camshafts and low-friction roller-type followers with hydraulic valve-play compensation help to optimise the valve management process. The pump-injector units, in turn, are operated by roller cam followers running on the exhaust camshaft.
The A3 Sportback 2.0 TDI is immediately available with front-wheel-drive in conjunction with a 6-speed manual gearbox, or with the Direct Shift Gearbox DSG.
The Direct Shift Gearbox DSG
The revolutionary Direct Shift Gearbox DSG combines the advantages of a conventional 6-speed manual gearbox with the qualities of a modern automatic, resulting in a superior drive concept. The driver benefits from enormous agility and driving enjoyment, with acceleration that is as smooth as it is dynamic, characterised by uninterrupted traction. This is combined with good economy thanks to low fuel consumption, and convenient operation.
The basis for this new development is a three-shaft six-speed manual gearbox which offers considerable variability in the selection of the transmission ratio. Thanks to the use of a twin multi-plate clutch with ingenious electro-hydraulic control, two gears can be engaged at the same time.
So how does DSG function? When driving, one gear is engaged. When the next gearshift point is approached, the appropriate gear is pre-selected but its clutch kept disengaged. The gearshift process opens the clutch of the activated gear and closes the other clutch at the same time with a certain overlap. The result is that the gear change takes place under load, and a permanent flow of power is thus maintained.
Incorporating optimum gearshift strategies, the control logic integrated in the transmission provides instantaneous, comfortable and smooth gearshifts virtually free of any jolts or judder. And by moving the gear lever in the manual gate or operating the standard-fit shift paddles behind the steering wheel as in a racing car, the driver can actively influence the choice of gears and the gearshift point at any time.
In the automatic mode, the driver can shift to the ultra-sporty S program in which upshifts are significantly retarded, downshifts advanced and the shifting process accelerated. A one-touch function accessed via the shift paddles on the steering wheel in addition temporarily calls up the manual mode, even in automatic modes D and S.
The 6-speed tiptronic
A 6-speed automatic transmission is still more the exception than the rule in the premium compact segment, yet it brings the driver palpable advantages compared with 5-speed versions. This is because the benefits of the greater spread of transmission ratios – 6:1 instead of the previous 5.5:1 – are not limited simply to superior operating economy.
As well as lower engine speeds in sixth gear helping to reduce fuel consumption and engine noise at high speeds, the shorter transmission ratio in first gear provides even more spontaneous "bite" and agile dynamics when accelerating.
Combined with the Dynamic Shift Program DSP, the six-speed tiptronic is a genuine all-rounder not simply in subjective terms and in the motoring pleasure it offers the driver. This automatic transmission, which first appeared on the Audi TT in 2002, is also notable for its compact design and low weight.
As well as the standard driving program D which places the emphasis more on economy, the 6-speed tiptronic has the ultra-sporty S program. In this program, the engine speeds at which the transmission shifts up are not only higher; the sport program avoids undesirable upshifts, for more harmonious driving at speed along winding roads.
A second shift gate has been added for extra ease of operation in the automatic mode, allowing the driver to select the speed manually if desired. And if the car is fitted with a multifunction steering wheel, the driver can also change from one driving mode to another simply by pressing the thumb-operated shift paddles .
The Dynamic Shift Program DSP provides extra drivability and comfort. It identifies different driving styles and determines the optimum gearshift point for every driver and driving situation.
quattro permanent four-wheel drive
On the Audi A3 Sportback quattro, a hydraulic multi-plate clutch varies the distribution of power between the front and rear wheels. This technical solution is indeed particularly suitable for cars with the engine fitted transversely, incorporating all the well-known advantages of an Audi quattro.
Offering permanent, situation-specific distribution of drive forces to all four wheels, quattro drive guarantees maximum traction and, as a result, optimum acceleration at all times. At the same time there are still ample reserves for transmitting cornering forces in the interests of directional stability and cornering safety.
The heart of this sophisticated drive system is the multi-plate clutch fitted between the driveshaft and the rear differential. A package of plates running in an oil bath within the clutch housing can be pressed together by controlled hydraulic power, thus providing variable torque distribution between the front and rear axle.
The more pressure is able to build up on the multi-plate clutch, the more drive torque can be transferred to the rear axle. The electronically controlled system responds instantaneously to any change in traction. And with its own oil supply featuring two axial-piston pumps quickly building up pressure, the clutch is able to intervene as required when the difference in rotating angles between the front and rear axle is as little as 45 degrees.
Power is distributed not according to a predetermined characteristic, but rather individually as a function of mechanical conditions, using both hydraulic and electronic signals. A data link provided by a CAN bus, that is an electronic data line, serves to register and evaluate a wide range of data fed in by other sensors and control units. The electronics control the clutch pressure, and thus the power transmitted in any given driving situation, via a control valve.
To this end, the control unit uses all kinds of information such as wheel and engine speed, road speed and engine torque. At the same time the system "learns" all about the driving situation and the driver's current preferences.
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