The superior principle of Audi TDI® cars clean diesel technology

The TDI® engines from Audi are superior engines that feature commanding performance and dynamic power. The 221 hp of the three liter TDI® that powers various Audi models, for example, provides about 80 hp of output per liter of displacementDisplacementThe total volume of air displaced by all the pistons within an engine block.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, especially in Europe, 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 torqueTorqueTorque is what causes rotational speed to change. Just as greater net forces cause greater linear accelerations, greater torques cause greater rotational or angular accelerations.Torque . Their propulsive power makes these diesel engines clearly superior to any comparable gasoline 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 gasoline engines, the propulsive power is always available when it's needed - and this contributes to a highly composed, relaxed style of driving. In the style of the classic American small block, the three liter V6 produces 406 lb/ft of torque at the crankshaft, which is available at just 1,750 rpm. The diesel engine produces 137 lb/ft per liter of displacement - a level that far surpasses that of the gasoline engine.

TDI® Engines are Efficient and Economical
Diesel engines make more efficient use of the energy in their fuels than do gasoline 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.

The outstanding efficiency of Audi's TDI® engines benefits the driver of a Q7 3.0 TDI® both when it comes to saving money and when it comes to covering long distances: with its 26 gallon tank, the car can cover more than 600 miles on a single fill up - saving the cost, time and annoyance of extra stops at the filling station.

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 gasoline 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