|CrossBlue Coupé. Click to enlarge.|
At the 2013 Shanghai Auto Show, Volkswagen will introduce the “CrossBlue Coupé” concept plug-in hybrid SUV. The automaker introduced the “CrossBlue SUV” concept—developed specifically for the US and Canada—at the North American International Auto Show earlier this year. (Earlier post).
The CrossBlue Coupé is powered by a plug-in hybrid system comprising a V6 turbo direct gasoline injection engine (TSI) and two electric motors; maximum system power is as much as 305 kW (409 hp). The Volkswagen accelerates to 100 km/h in 5.9 seconds, and its maximum speed is 236 km/h (147 mph). The CrossBlue Coupé has a combined fuel consumption of 3.0 l/100 km (78 mpg US) in the new European driving cycle (NEDC).
In hybrid mode fuel consumption (sub-cycle of the European ECE-R101 standard with discharged battery powered by just the TSI drive), the SUV consumes 6.9 l/100 km (34 mpg US) of fuel. This value enables a theoretical range of around 1,190 kilometers (739 miles) with a fuel tank capacity of 80 liters (21 gallons US).
The CrossBlue Coupé can be driven in all-electric mode over a distance of up to 33 kilometers (20 miles) at a maximum speed of 120 km/h (75 mph). To intentionally use this especially eco-friendly mode in urban areas, the driver can push a button to select the all-electric drive mode. As a production vehicle based on the new modular transverse matrix (MQB) (earlier post), the CrossBlue Coupé could also be fitted with conventional drive systems (four and six-cylinder engines) configured for a wide variety of fuels (gasoline, diesel, CNG).
The technical basis of the CrossBlue Coupé is the new Modular Transverse Matrix (MQB) of Volkswagen AG. Within the MQB, certain parameters are maintained uniformly across model series and brands, such as the mounting orientations of all engines. The modular component system also offers variable parameters that can be optimally and individually implemented in a wide variety of models. They include the wheelbase (CrossBlue Coupé: 2,980 mm), track widths and wheel sizes. All new MQB models are designed so that—along with the classic types of drive systems (petrol and diesel engines)—they can always be built as natural gas, hybrid or E-models as well.
In the concept car now being presented in Shanghai, the MQB front suspension and four-link rear suspension, the electromechanical MQB steering, the 220 kW / 295 hp V6 TSI of the EA390 engine series and an automatic 6-speed DSG (DQ 400 E) meld with electrical components. They include the lithium-ion battery in the center tunnel as well as the front E-motor with 40 kW and the rear E-motor with 85 kW.
The electric motors contribute 180 N·m (133 lb-ft) (front) and 270 N·m (199 lb-ft) (rear). In boosting—when the full power potentials of the engine and electric motors are combined—the drive system can produce a total system torque of up to 700 N·m (516 lb-ft).
The CrossBlue Coupé can be driven in five different operating modes: “Eco,” “Sport,” “Offroad,” “EV” and “Charge”. The default mode, in which the Volkswagen is started, is the classic “Eco” hybrid mode; it optimally manages use of the drive sources. The electric motors are used for propulsive power as often as possible in this mode. The driver can switch to the Sport mode by pressing a button; in this case, the vehicle exploits the maximum power of the drive system. As described above, there also available are an Offroad mode (permanent all-wheel drive); EV mode (driving with zero emissions); and a Charge mode (battery charging).
In EV mode, only the 85 kW E-motor at the rear axle provides propulsion. In all-electric driving, the V6 TSI is decoupled from the drivetrain by opening the clutch, and the engine is shut off. As soon as there is a need for TSI power—because of the battery charge state or other parameters—it is coupled to the drivetrain again, jolt-free, within fractions of a second.
In all-electric driving, the E-motors are supplied with energy from one of the eight modules that make up the lithium-ion battery. The battery has an energy capacity of 9.9 kWh and is housed in the center tunnel. The power electronics unit is integrated in the front engine compartment and operates at a voltage level of around 375 V. A DC/DC converter supplies the body electrical system with the 12 Volt electrical power it requires. The electric drive system does not impose any limitations on interior space. The battery can be charged either by external power sources (230 Volt connections) or while driving.
The driver can intentionally switch over to Charge mode (by pressing another button on the centre console). In this mode, the battery is charged by gasoline engine while driving, e.g. so that enough electrical energy can be stored in the battery for later zero-emissions driving at a destination in an urban area. Various other operating modes are automatically set as a function of the specific driving situation:
Coasting. As soon as the driver releases the accelerator pedal, the engine and electric motors are decoupled from the drivetrain, provided that the battery is sufficiently charged. This is referred to as “coasting”.
Battery regeneration mode. Whenever the driver releases the accelerator pedal or applies the brakes, and the battery is insufficiently charged, the two electric motors act as generators and feed energy recovered from the brakes into the lithium-ion battery. In this case, the TSI is also shut off and decoupled from the drivetrain.
Boosting. When very sporty performance is called for, the E-motors form an alliance with the TSI. This combining of forces is known as “boosting”, in which the CrossBlue Coupé is driven by all four wheels.
Offroad with “propshaft by wire.” All four wheels are also driven whenever the driver intentionally activates Offroad mode (once again by pressing a button on the centre console). In this case, and when the battery’s charge is low, the front electric motor—which is now supplied with energy by the V6 TSI—operates exclusively as a generator and supplies electrical power to its counterpart at the rear axle. Since the energy for driving the rear wheels flows by wire and not mechanically, this is referred to as “propshaft by wire”. The all-wheel drive system is still operational, even when the battery is in a low charge state, because the TSI drives the rear E-motor via the front E-motor in Offroad mode.
The 6-speed gearbox operates with short actuating travel. The selection lever was furnished with a new by wire switch logic: Like a joystick, the selection lever continually returns to its middle position; the classical “D”, “R” and “N” levels are activated by a short kick; shifting into the “P” position is by a separate pushbutton that is ergonomically integrated in the selector lever. The start-stop button (“Engine”) was integrated on the right of the gear shift lever.
Located centrally on the center console is a 10.1 inch touchscreen with proximity sensors. The large touchscreen is not only used to control all infotainment and entertainment functions, but also to access the status of the hybrid system. The type of representation changes according to the driving mode.
In the “Sport” mode, buildings are “suppressed” in the 3D map representation; they recede for a clearer and less busy graphic image during fast driving. On the other hand, an animated 3D representation is shown in the “Eco” mode, in which buildings rise up on the horizon.
The type of information shown in the instrument cluster also changes between the “Eco” and “Sport” modes. In the “Eco” mode, the Powermeter and battery status are two of the items shown in the left round instrument, while the right instrument assumes speedometer and fuel gauge functionalities. In the middle instrument—identical in both modes—users can access functions such as the gear indicator, driving ranges, compass, weather, clock and—in Navigation mode—the remaining distance to the destination.
In “Sport” mode, the left round instrument shows the tachometer and displays torque and battery status at its center; the Powermeter is also “reduced”.
The ports for the fuel tank and battery were uniformly integrated into the design of the CrossBlue Coupé. As is usual with Volkswagen, the fuel filler neck is located under a lid on the right side of the vehicle. The cover for the electrical outlet is located symmetrically on the left side. It consists of one socket for charging the high-voltage battery and another for connecting electric devices; this interface (16 A, 230 V) makes the CrossBlue Coupé an emergency generator as needed.