Audi wheeling out all-road shooting brake plug-in hybrid concept at Detroit show; the first e-tron quattro

Shooting brake concept. Click to enlarge.

Audi will unveil an all-road shooting brake plug-in hybrid concept at the North American International Auto Show (NAIAS) in Detroit. The two-door car is a crossover; its hybrid drive demonstrates a new form of quattro drive—the e-tron quattro.

The Audi allroad shooting brake represents the first time that Audi has combined the all-road and e-tron form languages. The compact crossover plug-in hybrid has a low fuel consumption figure of 1.9 liters of fuel per 100 km (123.8 mpg_US), equivalent to 45 g CO₂ per km (72.42 g/mile) based on the relevant ECE standard. Its total driving range is up to 820 km (510 miles).

The show car combines sex appeal, highly efficient e-tron-quattro technology that produces 300 kW of power yet only consumes 1.9 l/100 km (123.8 US mpg) of fuel and cutting-edge electronic applications. We are offering very concrete glimpses of the near future in this show car.

—Prof. Dr. Ulrich Hackenberg, Member of the Board of Audi AG, Technical Development

The plug-in hybrid drive also delivers impressive performance with 300 kW (408 hp) of system power and a system torque of 650 N·m (479 lb-ft). The show car, which weighs around 1,600 kg (3527 lb) without the driver, accelerates from 0 to 62 mph in 4.6 seconds, with a top speed of 250 km/h (155.34 mph).

The 2.0 TFSI engine in the Audi allroad shooting brake outputs 215 kW (292 hp) of power and generates 380 N·m (280 lb-ft) of torque. The transverse mounted two-liter four-cylinder with a large turbocharger is a high-end engine. In part-load operation, indirect injection supplements direct gasoline injection to improve fuel economy; the exhaust manifold that is integrated in the cylinder head enables high-performance thermal management.

The 2.0 TFSI operates together with a disc-shaped electric motor via a decoupling clutch; the electric motor outputs 40 kW of power and 270 N·m (199.14) of torque. It is integrated in the six-speed e-S tronic. The dual clutch transmission, which shifts at lightning speed, sends torque to the front wheels.

A second electric motor, which is separate from this drive unit, is mounted to the rear axle. It supplies propulsive power at low and moderate vehicle speeds with its maximum power of 85 kW and 270 N·m (199 lb-ft) of torque. It can also be operated in tandem with the motor and engine at the front axle if the hybrid management system decides that all-wheel drive makes sense. In such situations, e.g. on a slippery road or in light off-road conditions, this essentially makes the Audi allroad shooting brake an e-tron quattro.

Located just forward of the rear axle is a lithium-ion battery that consists of eight modules. It contributes towards a balanced distribution of weight, and it hardly affects cargo capacity at all. The liquid-cooled battery has an energy capacity of 8.8 kWh, which is enough for 50 km (31 miles) of all-electric driving. An Audi wall box is used for stationary charging; it can operate with different voltages and plug connector types, and it regulates the energy transfer conveniently and intelligently.

Drive select management offers three driving modes. There is the EV mode, which can be selected by a button on the multifunction steering wheel; it prioritizes all-electric driving. Here, the front drive unit is inactive, and the electric motor at the rear axle can rapidly accelerate the two-door car to a top speed of 130 km/h (81 mph).

In Hybrid mode, the drive sources work together in various ways as necessary. In many situations, the electric motor in front acts as a generator—driven by the engine, it charges the battery, and this extends the car’s effective electric driving range.

In Sport mode, which the driver can select via the Audi drive select sysdi, tem, the car’s full system power is available. When a high level of power is demanded by the driver, the electric motor at the rear axle works together with the 2.0 TFSI in a boost mode, in which both drive units output propulsive power.

Depending on the driving situation, releasing the accelerator pedal can cause all drive units to be decoupled, or it can result in energy recovery by regenerative braking. In the first case, the show car coasts with zero emissions since the combustion engine is shut off; in the latter case, braking energy is fed back into the high-voltage battery.

The driver can use the “Hold” and “Charge” functions in the MMI user interface to specifically influence the battery's charge state, e.g. to increase storage of electric energy so that it can be used over the final kilometers to the destination.

Chassis. An electro-mechanical steering system is at work in the chassis of the Audi allroad shooting brake; it works together with a MacPherson front suspension and a four-link rear suspension. For off-roading, the crossover features high ground clearance, compact wheelbase, short overhangs and electric quattro drive. It has a taut and sporty stance on the road, and the Audi drive select vehicle dynamics system offers various modes to the driver. Size 255/40 tires are mounted to its 19-inch wheels.

Source: Green Car Congress