Published September 28, 2012
By Philippe Crowe
Yesterday in Paris, Audi provided a glimpse of its future design language, along with automotive and drive concepts, through its Audi crosslane coupé concept car.
The concept is powered by a plug-in hybrid drive based on a purpose-designed
1.5-liter three-cylinder TFSI and two electric motors, with fuel consumption according to Audi of only 1.1 liters per 100 km (213.81 U.S. mpg).
The Multimaterial Space Frame of the compact Audi crosslane coupé is comprised of three materials – aluminum, carbon fiber-reinforced polymer (CFRP), and glass fiber-reinforced polymer (GFRP). The concept car has an un-laden weight of about 1,390 kg (3,064.43 pounds), including the 17.4-kwh lithium-ion battery.
The aluminum profiles form a continuous, rigid structure around the occupant cell. Beams beneath the front lid join the single-frame grille, which performs a supporting function and is also made from aluminum, with the occupant cell.
The front and rear crash structures are made from CFRP and the supporting CFRP structures inside the occupant cell include the inner sills, the center tunnel, the bulkhead, and the cross-members in the floor. Surface GFRP components with partial CFRP reinforcements complete the body concept.
Audi is convinced that the highly integrated Multimaterial Space Frame is the right path to the future. Its weight is of the same magnitude as a monolithic body of CFRP. It also offers convincing advantages in terms of costs to the customer and its energy usage in a life cycle assessment.
The plug-in hybrid drive of the Audi crosslane coupe is described by Audi as a dual-mode hybrid. It combines a combustion engine, two electric motors and a single-stage transmission; its total system power is 177 horsepower.
The Audi crosslane coupé sprints from zero to 100 kph (62 mph) in 8.6 seconds, or 9.8 seconds in pure electric mode. The car’s top speed is 182 kph (113.09 mph).
The lithium-ion battery has an output of 17.4 kwh, which Audi considers sufficient for an operating range of around 86 km (53.44 miles) in pure electric mode.
The combustion engine is a purpose-developed three-cylinder TFSI with a displacement of 1.5 liters, delivering an output of 130 hp and 147.51 pound-feet of torque. The three-cylinder engine is coupled to an electric motor (EM 1), which acts primarily as a starter and an alternator. It develops an output of 68 hp and 154.89 pound-feet of torque. Electrical traction is provided by the second electric motor (EM 2) developing 116 horsepower and 184.39 pound-feet of torque.
The transmission makes it possible to connect the combustion engine with the alternator to the remainder of the drivetrain by means of a claw clutch.
The dual-mode hybrid concept enables different operating modes. From 0 up to 55 kph (34.18 mph), drive power is supplied solely by the EM 2, which draws the energy it needs primarily from the battery. In serial mode, the combustion engine and the alternator (EM 1) produce electrical energy to support, relieve or substitute the battery should it be discharged.
The electric mode is possible up to 130 km/h (80.78 mph). Starting at about 55 kph (34.18 mph) the drive system engages the TFSI engine and the alternator (EM 2) – in this hybrid mode, the drive sources combine to optimize both efficiency and performance. Above 130 kph (80.78 mph), the three-cylinder engine becomes the main drive source but the EM 1 can support it if required.