For a fraction of a second the intake and exhaust valves in the cylinder are both open, allowing fresh air to flood into the combustion chamber. It propels the exhaust gas swiftly towards the exhaust manifold, helping the turbocharger to press fresh oxygen into the cylinder. During this process the injection valve stands still, before pumping the fuel under high pressure directly into the cylinder when the other valves have closed. The effect: even at low speeds, the engine has a rich supply of oxygen and provides an impressive torque. In other words, you can cut back on engine capacity – if you use sophisticated technology.

Audi’s development engineers have turned to downsizing in order to reconcile fuel consumption, environmental impact, and driving pleasure. The principle: a reduction in the engine volume and number of cylinders, while fuel consumption drops as a result of lower frictional losses. At the same time, the turbocharger or compressor ensures solid performance – thanks to technical highlights such as direct fuel injection and variable valve timing. This concept is allowing Audi to make petrol engines fit for the years to come. “Given the technology available today, the thing that makes most sense from an environmental perspective is to enhance the internal combustion engine”, says Axel Eiser, Head of Petrol Engine Development at Audi. “To achieve this, we are adopting a downsizing strategy, the approach which in our opinion offers the greatest potential.”

The star performer among the new generation of engines is the 2.0 TFSI. Depending on the precise version concerned, the four-cylinder engine offers more than 100 PS per liter of engine capacity. At the same time, it demonstrates that the concept of downsizing in fact comprises a number of different innovations: for example, it is the first large-series turbocharged direct injection petrol engine in the world.