Please, let yourself tell nothing. In principle, a petrol engine needs a consistently high compression to generate next to a good torque also a low consumption. Unfortunately, the principles based on the fundamental ideas of Atkinson and Miller are described not always correctly.

Commenting on the new 2.0 TFSI in the A4 from 2015: Yes, it has more displacement again and it is also true that it does not use this in principle at partial load. It then feels like a 1.4 litre. But be careful, if one presses the accelerator pedal right down, it mutates again to 2.0 litre and that without turbo lag such as possibly at the 1.4 litre.

So that's why the higher torque compared with the competitiors because torque as catalog value is always measured at full load. But we begin with the partial load, probably by far the most frequented operating range. For whoever demands already constantly 320 Nm?

Another requirement for these other engine must be clarified first that for a turbo engine exorbitantly high compression ratio of 11.7 : 1. Just for comparison: It was before the Miller treatment 9.6 : 1. Then the engine still has the much needed control in order to be able to shorten the intake at partial load significantly. Finally, also not unimportant, the electronically controlled wastegate turbocharger.

From these ingredients we are building indeed no miracle engine now, but already something new from which is to hope that with even more intensive use of the principle, a really relevant consumption difference arises someday. After all, we already have the strengths of its crisp performance.

So we get at part load a shorter intake time due to much earlier than usual closing intake valves. The thereby too low filling must be compensated by the boost pressure in such a way that together with the high geometrical compression ratio, a good, but not too high discharge pressure arises.

That was the downsizing part now. Would be maintained the relatively high boost pressure at full load and normal intake opening times, we would have before us a strong knocking and soon ruined engine. So there must be more likely taken back the boost pressure, whereby we now refuse to give information about the produced amount of air.

Nevertheless, it can be assumed that it is easier and less time-consuming to change the valve control and to correct the boost pressure only slightly and perhaps even downwards than to bring a turbocharger to significantly higher rpm. Because the indication of the maximum torque states almost nothing about the response of the engine, we have a second performance advantage here

So once again: When changing from partial to full load, the intake time is significantly extended, but the control of the turbocharger must ensure that in each case the best possible compression (not too high and not too low) is achieved. In addition, the combination of indirect and direct injection, the latter with 250 bar ensures a good mixture distribution. Effective thermal management is also available at the other engines.

The original Atkinson approach is based on a longer working stroke in order to use the energy of the expanding mixture better. Even that meets the engine when it provides a filling meant for 1.4 litres torque in the working stroke 2 litres of torque. Just a pity that one more likely the relatively unimportant Tornado line in the body at Audi provides to the fore as this new engine concept. 12/15