The modular efficiency platform
Sportiness and efficiency are not contradictory at Audi – quite the contrary: They are interdependent and foster one another. The engineers can draw on a comprehensive arsenal when developing a vehicle: the technologies of the modular efficiency platform.
Audi is a powerful driver of progress when it comes to engine technologies. The downsizing principle – the substitution of forced induction for displacement – reduces fuel consumption and boosts performance. Direct injection is now standard in all engines, and most are turbocharged or supercharged.
The 1.6 TDI is currently the most efficient engine in the Audi lineup. Used in numerous models in the A1 and A3 series, it consumes 3.8 liters per 100 km (61.90 US mpg) on average in the NEDC, corresponding to CO2 emissions of 99 grams per km (159.33 g/mile). The brand’s gasoline engines also shine. The 1.4 TFSI in the A3 and A3 Sportback produces 103 kW (140 hp) and when combined with the S tronic emits just 110 grams CO2 per km (177.03 g/mile).
The sporty four-cylinder engine uses a technology from the modular efficiency platform that puts Audi ahead of the competition: The cylinder on demand (COD) system shuts down two of the four cylinders at low and moderate loads as well as when coasting by closing the valves. They are reactivated when the driver steps down hard on the accelerator. The COD technology is used in a similar form in the powerful 4.0 TFSI, a V8 biturbo.
The Audi modular efficiency platform includes many other technologies. Some examples include the intelligent thermal management system that quickly brings the engine up to operating temperature after starting, common-rail injection, turbocharging, the reduction of internal friction, the demand-controlled drive for the auxiliaries, the start-stop system and the Audi valvelift system (AVS), which varies the lift of the valves depending on the situation. The latter is the basis for the COD technology.
Two particularly advanced solutions recently debuted in production vehicles: the exhaust manifold integrated into the cylinder head and dual injection in the combustion chamber and the induction pipe. In some TDI engines, clean diesel technology significantly reduces NOx emissions for even cleaner exhaust.
Audi considers its automobiles in their entirety, thus efficiency extends far beyond the engine. Most manual and automatic transmissions, for instance
the S tronic units, have a tall top gear. This reduces engine speed and therefore fuel consumption. In many cases the transmission is integrated into the engine’s thermal management system.
On the chassis, the electromechanical steering standard in most models contributes to the low fuel consumption. There is also great potential in tires optimized for low rolling resistance. In the large models, the adaptive air suspension lowers the body several millimeters at high speeds to reduce drag. Another important efficiency factor is energy management in the complete vehicle. It begins with the automatic air conditioning and ends with the LED headlights, which consume a particularly low amount of electricity.
The painstaking aerodynamic fine-tuning that all Audi models undergo comes into play primarily at faster highway speeds. The bodies follow the principles of lightweight construction. In many models, the body includes parts made from ultra high-strength steel and aluminum. The bodies of the R8, the A8 and the TT are made either mostly or entirely of this lightweight metal. The body of the luxury sedan thus weighs nearly 100 kg (220.46 lb) less than a body made from steel sheet, which corresponds to fuel consumption reduction of about 0.4 liters per 100 km. Audi also pays strict attention to low weight in all other areas, from the engine to the interior.
The brand’s assistance systems help the driver to drive more efficiently. The onboard computer with efficiency program monitors energy flows in the car, gives tips for saving fuel, and integrates a redesigned shift indicator. Audi online traffic information, an Internet service from Audi connect, warns the driver in real time about traffic jams and delays along the planned route. This helps to save not just time, but also fuel.