Although the second-generation Audi R8, which made its debut at the 2015 Geneva Motor Show, is similar in appearance to the outgoing model, new construction methods have reduced the weight of the car. Re-developed from the ground up, according to Audi, power will come from two variants of the 5.2-L FSI direct injection Audi V10 gasoline engine. Two further variants will also be available: an e-tron battery electric and an LMS race variant.
Power and torque have risen for the two V10-powered models. For the base V10 model, power output is a claimed 397 kW (532 bhp) with peak torque of 540 N·m (398 lb·ft) at 6500 rpm. This engine enables the car to accelerate from rest to 100 km/h (62 mph) in 3.5 s and on to a top speed of 323 km/h (201 mph). The more powerful V10 plus produces 449 kW (602 bhp) with peak torque of 560 N·m (413 lb·ft) at 6500 rpm. With this engine, the car will reach 100 km/h (62 mph) from rest in a claimed 3.2 s and a top speed of 330 km/h (205 mph).
The engine features indirect and direct fuel injection, for both lower fuel consumption and enhanced engine output depending on the situation. Fuel consumption is also benefited from cylinder on demand technology that deactivates injection and ignition to one of the banks of five cylinders and by engine stop-start. The dry-sump engine is assembled by hand at Audi’s Hungarian engine plant.
Both V10 variants are equipped with a seven-speed S-tronic automated transmission, which offers three drive modes and a manual override. Four-wheel drive is fitted as standard. A launch control system manages full-throttle acceleration from rest. When power is not needed, the R8 is equipped with a coasting system. This is activated when the driver lifts off at speeds exceeding 55 km/h (34 mph). Both transmission clutches are opened and the car coasts to reduce fuel consumption.
Audi quotes fuel consumption of 11.8 L/100 km (19.9 mpg US) and CO2 emissions of 275 g/km for the R8 V10. This increases to 12.4 L/100 km (19.0 mpg US) with CO2 emissions of 289 g/km for the V10 plus. Audi claims a reduction in fuel consumption of up to 10% over the previous model.
For the revised four-wheel-drive system, the front axle is now equipped with an electrohydraulically activated multi-plate clutch in place of a viscous-coupling. Audi claims that drive torque can be directed wherever it is needed, with up to 100% torque distribution to either front or rear wheels. A mechanical differential lock is used for the rear axle.
Suspension is by aluminum double wishbones for all four wheels, and variable damping from magnetic ride shock absorbers is available as an option.
Electromechanical power steering is standard. Dynamic steering is offered as an option with variable ratio steering, which senses road speed and the settings chosen for the dynamic handling system.
Standard fitment on the base model are 19-inch wheels with 245/35 section tires in front and 295/35 section tires at the rear; 20-inch wheels are standard equipment for the R8 V10 plus and optional for the base models. With 20-inch wheels, tire sizes are 245/30 at the front and 305/30 at the rear.
Braking equipment also varies according to model. The R8 V10 is fitted with steel brake discs, while the R8 V10 plus is equipped with carbon fiber ceramic discs.
Audi’s drive select dynamic handling system gives drivers a choice of four modes: comfort, auto, dynamic, and individual. System behavior is governed by sensors monitoring engine characteristics, steering, transmission, and options such as the magnetic ride system, exhaust flaps, and dynamic steering—when fitted.
V10 plus models come with a new performance mode, available as an option for V10 models, activated from a button on the steering wheel. Drivers can choose from dry, wet, or snow settings, which will automatically engage the ESC electronic stability control system.
Audi engineers have devised a new method for spaceframe construction that reduces the weight of the body shell to 200 kg (440 lb), a claimed 15% lighter than before, for a total vehicle unladen weight of 1555 kg (3428 lb). Carbon fiber reinforced plastics are used in the construction of the B-pillars, central tunnel, and the rear wall. A framework formed from the front section, roof arch, and rear section is produced with cast aluminum nodes and aluminum profiles, some using new alloys. Audi claims that torsional rigidity is improved by some 40%.
The R8 is 4.42 m (14.5 ft) long, 1.24 m (4.1 ft) tall, and 1.94 m (6.4 ft) wide or about 40 mm (1.6 in) wider than before. The wheelbase is 2.65 m (8.7 ft) long.
LED headlamps are standard equipment, with laser high beams offered as an option, which doubles the range of the high beam to 600 m (1970 ft). Where fitted, the laser high beam is made of four high-powered laser diodes that generate a blue laser beam with a wavelength of 45 nm. The blue light is converted to white using a phosphor converter with a color temperature of 5500 K, a color suited to human vision. The laser lighting is activated at speeds above 60 km/h (37 mph). A camera-based sensor system detects other road users and adjusts the light pattern to avoid dazzle.
The e-tron version benefits from the changes to the construction of the car. A T-shaped battery pack is integrated into the center tunnel and behind the cabin. Audi produces the lithium-ion cell, which offers a capacity of 92 kW·h compared with 49 kW·h for the previous developmental model. This provides a claimed electric range of 450 km (280 mi) instead of 215 km (134 mi).
Audi claims that energy density has been increased from 84 to 154 W·h/kg for the production model. The car can be charged using both direct and alternating current. Audi claims a full charge is possible in less than two hours.
The R8 e-tron offers claimed acceleration from rest to 100 km/h (62mph) in 3.9 s with top speed limited to either 210 km/h (130 mph) or 250 km/h (155 mph).Continue reading »