Engine

Fascinating dynamics and astonishing efficiency – the new Audi S3 goes straight tro the top of its class. The sprint from 0 to 100 km/h (62.14 mph) takes just 4.8 seconds when equipped with the optional six-speed S tronic (5.2 seconds with the manual transmission); Its electronically governed top speed is 250 km/h (155.34 mph). The new S3 with S tronic consumes on average just 6.9 liters of fuel per 100 km (34.09 US mpg), a CO₂ emission of 159 grams per kilometer (255.89 g/mile) (7.0 liters per 100 km [33.60 US mpg], 162 grams per kilometer [260.71 g/mile]). Compared to the previous model with manual gear shift the consumption has fallen 1.5 liters per 100 km (156.81 US mpg). That equates to CO₂ emissions of 35 grams per kilometer (56.33 g/mile).

The 2.0 TFSI marks another milestone in the downsizing strategy of Audi. Redesigned from scratch, the only thing it has in common with its predecessor, which was voted “International Engine of the Year” five times in a row, is the displacement of 1,984 cc (bore x stroke 82.5 x 92.8 millimeters, [3.25 x 3.65 in]). The four-cylinder engine is compactly built and weighs just 148 kilograms (326.28 lb), a good five kilograms (11.02 lb) less than its predecessor. At 5,500 rpm there is nominal output of 221 kW (300 hp), at 6,800 revolutions the rev limiter kicks in. From 1,800 to 5,500 rpm it delivers 380 Nm (280.27 lb-ft) of torque.

As a genuine sports engine, the 2.0 TFSI responds spontaneously to commands from the gas pedal. Its sonorous sound becomes particularly intensive when the standard Audi drive select is working in dynamic mode. In this case the engine responds more directly to commands from the gas pedal; with the S tronic gear change the twin clutch reacts in a flash. In the event of greater loads and revolutions per minute the two sound flaps in the exhaust system open, producing an even richer sound. Two balance shafts, which rotate in opposite directions from one another at twice the revolving crankshaft speed, ensure highly efficient mechanical functioning.

Lots of details underscore the high-performance character of the new four-cylinder engine. Modified aluminum pistons and high-strength, re-pivoted piston-rods transfer the forces. The gray cast iron crankcase has been reinforced at the main bearing seats and at the main bearing cover. The cylinder head is made of a new, particularly lightweight aluminum-silicon alloy characterized by high strength and temperature resistance.

The large turbocharger, another newly developed product, is designed for exhaust gas temperatures of up to 1,000 degrees Celsius. With a maximum charge pressure of 1.2 bar it concentrates 1,000 kilograms (2204.62 lb), in other words 850,000 liters (30,017.47 cu ft) of air per hour. An efficient air-air-charge air cooler considerably lowers the temperature of the compressed air, thereby increasing the mass available on combustion, and thus the oxygen content. The electronically-controlled waste gate works extremely quickly and precisely; it reduces the charge cycle work, as under partial load it lowers the basic charge pressure and thus the exhaust gas pressure.

Dual injection: Fit for the future
In many areas of engineering the 2.0 TFSI delivers pioneering solutions from the Audi efficiency module. One of these is additional indirect injection, which complements the FSI direct fuel injection. It reduces consumption and particle emission – the four-cylinder already adheres to the limits, which in the second level of the Euro-6 norm will apply from 2017. The FSI injection, which works at pressures up to 200 bar, is used when starting and at higher greater loads: each of the enlarged injection valves has six holes.

The four cylinders are well filled at all times. The inlet camshaft can be infinitely adjusted through a crank angle of 60 degrees, the outlet camshaft by 30 degrees; moreover, on the outlet side the Audi valvelift system varies the valve lift in two stages. What are known as drumble valves direct the incoming air in a specific direction.

The exhaust manifold is integrated in the cylinder head and has coolant flowing around it – a solution, which lowers the temperature of the waste gas and accelerates the warming of the engine after cold start. With the 2.0 TFSI’s innovative thermal management system, two rotary slide valves consolidated in a single module regulate the flow of coolant. They ensure that after ignition the engine oil quickly reaches operating temperature. This way they always achieve the best relationship between minimal friction and high thermodynamic efficiency.

An innovative coating for the piston skirt and the anti-friction bearing of the balance shafts keep friction low, the oil pump operates according to needs. A standard start-stop-system rounds out the efficient technology package.

The equipment, data and prices specified in this document refer to the model range offered in Germany. Subject to change without notice; errors and omissions accepted.