The TDI ® engines from Audi are superior engines that feature commanding performance and dynamic power. The 240 hp of the three liter TDI® that powers various Audi models, for example, provides about 80 hp of output per liter of displacement - a level that just a few years ago was reserved for the sports car segment. Thanks to their extremely low consumption levels and their proliferation TDI® engines have become the most successful efficiency technology in the world. When driven under realistic, mixed driving conditions, TDI® cars generally also beat comparable models with hybrid drives.
TDI® Engines Feature High Propulsive Power
The greatest strength of all Audi diesel engines is their tremendous torque. Their propulsive power makes these diesel engines clearly superior to any comparable petrol engine. This mighty power is also available at extremely low revs - just a little over idle speed - as a smooth but insistently applied impulse that requires only the slightest pressure on the accelerator. In sharp contrast to many stressed, high revving petrol engines, the propulsive power is always available when it's needed - and this contributes to a highly composed, relaxed style of driving.
TDI® Engines are Efficient and Economical
Diesel engines make more efficient use of the energy in their fuels than do petrol engines. This fundamental principle of physics has been refined through many solutions that Audi has played a major role in developing - including the four-valve technology that ensures optimum filling of cylinders in every situation and the principle of variable vane geometry for turbochargers.
TDI® Engines are Quiet and Comfortable
The modern direct injection diesel engines from Audi are hardly perceptible to the ears of their passengers - their operation is virtually indistinguishable from that of a petrol engine. This is thanks in part to the extensive development efforts of Audi's engineers. Selective ribbing on the engine blocks inhibits vibrations during operation; all pathways on the engine mounts and car body that could transmit vibrations to the interior have been eliminated.
The common rail technology is the source of another major advance. With it, the multiple injections per cycle capability can generally be freely selected in the control unit. The pilot injections, which are widely spaced from the main injection, provide a gradual increase in pressure that makes the combustion process smoother. The innovative piezo injectors used by Audi further reinforce this effect with their extremely fast and precise switching - with these injectors, the hard "knocking" and metallic rattling at partial load is history.