The 3.2 FSI V6 with Audi valvelift system
The 3.2 V6 FSI – which features as a basic engine with an output of 255 bhp in the Audi A8, A6 and A4 – displays all the characteristics of an ultramodern petrol engine: FSI petrol direct injection with
demand-controlled fuel supply, four valves per cylinder and highly effective exhaust emission control.
FSI engines develop superior power and dynamism to conventional units with indirect manifold injection – and they do so with a very high stand-ard of fuel economy. With this remarkable achievement, Audi is opening up a new dimension in the efficiency of standard petrol engines, demonstrating once again the brand’s proverbial “Vorsprung durch Technik”.
The FSI petrol direct injection system confirmed its unique potential in what must be the most challenging endurance test in the world: a power unit with FSI direct injection drove the Audi R8 to victory on four occasions in the Le Mans 24 Hours.
The evolutionary version that powers the Roadjet Concept includes two technologies that double the specific advantage of FSI technology. Because with a fixed intake manifold together with integral vacuum reservoir – as opposed to the variable intake manifold of the production version – the 3.2 FSI can be configured systematically as a sports engine.
The six-cylinder engine in addition features a new valve control principle by the name of Audi valvelift system. In the form of two-stage cam lift adjustment, it is able to vary the degree of valve opening according to load and engine speeds.
What this means in practice is that in flowing traffic, the engine produces a decidedly smooth, relaxing response to only moderate use of the accelerator pedal, with impressive pulling power in reserve that results in outstandingly low fuel consumption.
But as soon as the driver ups the tempo, the 3.2 engine reveals its qualities as a highly talented athlete. It responds with bite to even minimal movements of the accelerator and moves fleet-footedly right up to the speed dictated by the limiter, which only cuts in at 7,500 rpm. What is particularly remarkable is that the power output rises constantly virtually all the way up to that point.
This V6 engine delivers its maximum output of 220 kW (300 bhp) at 7,000 rpm; its peak torque of 330 Nm is available at 4,500 rpm. The Roadjet Concept 3.2 FSI accelerates to 100 km/h in 6.4 seconds, and its top speed is electronically governed at 250 km/h.
No less astonishing is the average fuel consumption of this evolutionary concept: the Roadjet Concept covers 100 kilometres on just 10.4 litres of Super Plus – despite the Roadjet Concept's higher weight and larger frontal area, this figure is a few tenths of a litre better than its production counterpart in the A4 3.2 quattro, which develops 45 bhp less!
The combination of FSI and Audi valvelift system unquestionably demonstrates how much potential Audi's petrol engines of the future will still be capable of mobilising, with a view to delivering even more driving fun and efficiency. And that future is not far off: the underlying technology is already so mature that it could start finding its way into production in a few months' time.
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