The new naturally-aspirated 5.2-liter V10 engines in the newly introduced second-generation high-performance Audi R8 (earlier post) introduce two new efficiency technologies to that platform: supplementary port fuel injection, and cylinder-on-demand, along with a new start-stop system.
The ten-cylinder engine is available in two versions.
|R8 V10. Click to enlarge.|
In the R8 V10, it develops a power of 397 kW (540 hp) from its 5,204 cc displacement and a torque of 540 N·m (398.3 lb-ft) at an engine speed of 6,500 rpm. The sprint from 0 to 100 km/h (62.1 mph) takes just 3.5 seconds, and it can reach a top speed of 323 km/h (200.7 mph).
The R8 V10 plus is even more powerful and is the fastest series-production Audi yet. It develops 449 kW (610 hp) and its maximum torque of 560 N·m (413.0 lb-ft) is available at 6,500 rpm. Acceleration from 0 to 100 km/h (62.1 mph) takes 3.2 seconds, 0 to 200 km/h (124.3 mph) 9.9 seconds; top speed is 330 km/h (205.1 mph).
Audi has used a dual injection system that combines direct injection with indirect injection into the intake manifold in some of its other, lower-range engines. (Earlier post.) In part-load operation, the indirect injection supplements direct gasoline injection to improve fuel economy and to reduce the output of particulates from the engine.
The R8 features yet another innovative system in the form of COD (cylinder-on-demand). It shuts off one of the two cylinder banks by deactivating injection and ignition.
The R8 V10 consumes an average of 11.8 liters of fuel per 100 kilometers (19.9 US mpg) with CO2 emissions of 275 grams per kilometer (442.6 g/mi). For the R8 V10 plus those values are 12.4 liters per 100 kilometers (19.0 US mpg) and 289 grams per kilometer (465.1 g/mi). A fuel consumption reduction of up to 10 percent compared to the previous model is also due to the new start-stop system.