|BMW i8 Concept Spyder. Click to enlarge.|
Following on the presentation of the BMW i3 Concept and BMW i8 Concept coupé at the Frankfurt show in 2011 (earlier post), the BMW Group has introduced a third i Model: the BMW i8 Concept Spyder. Like the i8 coupé concept, the BMW i8 Concept Spyder with eDrive is a plug-in hybrid. The 96 kW (131 hp) electric motor on the front axle works in tandem with a TwinPower Turbo three-cylinder gasoline engine sending 164 kW (223 hp) through the rear wheels.
Both power units are in-house BMW Group developments and generate an aggregate system output of 260 kW (354 hp) and peak torque of 550 N·m (406 lb-ft). The BMW i8 Concept Spyder accelerates from 0 to 100 km/h (62 mph) in five seconds on the way to an electronically governed top speed of 250 km/h (155 mph). The two-seater burns three liters of gasoline per 100 kilometres (equivalent to fuel economy of 78.4 mpg US) in the European test cycle.
The electric motor sources its energy from a lithium-ion battery pack which can be fully charged from a domestic power socket in less than two hours. The high-output battery is located in the energy tunnel between the front and rear axle modules; the space-saving and well-balanced packaging of this and other drive and chassis components gives the sporting two-seater ideal 50:50 weight distribution.
With its battery fully charged, the BMW i8 Concept Spyder can cover up to 30 kilometers (19 miles) on electric power alone. If required, a high-voltage alternator hooked up to the combustion engine generates extra power, which is then stored in the hybrid battery. This range-extending function during the course of a journey allows the two-seater to travel further between charging stations.
The BMW i8 Concept Spyder can send power through the front, rear or all four wheels at the same time. Intelligent control electronics ensure that the optimum drive configuration is available for the situation at hand. The driver can view the driving mode currently engaged and monitor the activity of the two drive sources on the large information display in the cockpit. Furthermore, the electronic systems ensure maximum energy recuperation under braking or when coasting.
Compared with the original coupé variant of the BMW i8 Concept, the BMW i8 Concept Spyder has a slightly shorter wheelbase and overall length. Like the coupé, the BMW i8 Concept Spyder is built around the LifeDrive architecture (earlier post), a fusion of independent functional units. For example, the carbon-fiber-reinforced plastic (CFRP) Life module gives the car an extremely lightweight passenger cell, while the Drive modules—made primarily from aluminium components—bring together all the car’s operational driving functions, such as the powertrain, chassis and safety structure.
Lightweight design, encompassing the use of innovative materials, has allowed the unavoidable additional weight of the high-output hybrid drivetrain to be cancelled out in full. The LifeDrive architecture also has been adapted to the sports car character of the BMW i8 Concept Spyder. The front and rear axle modules are connected by an “energy tunnel”, which houses the battery pack. This allows the engineers to give the car a low center of gravity and ideal balance. The distinctive two-way split of the LifeDrive concept is also reflected in the car’s design, which renders the basic elements of the body clearly distinguishable. Expressive surfaces and precise lines create a harmonious transition from one module into another. This overlap and interlocking of surfaces and lines—“layering” in BMW i speak—is displayed both on the body and in the interior of the new car.
Connectivity. BMW i drivers will have a new generation of driver assistance systems at their disposal to enhance both safety and comfort, such as the camera-based proactive Collision Warning system, Parking Assistant and Traffic Jam Assistant.
In addition, BMW i is developing an array of connectivity functions which provide a seamless link between its models and their owners’ lives outside the car. Remote functions accessed via a smartphone help users to locate their car in large car parks (CarFinder); show nearby charging stations; allow the battery to be charged at pre-set times; and inform drivers on the current status of their vehicle. Further, the battery and interior can be brought up to peak operating temperature before the driver sets off on a journey.
The Last Mile Navigation function assists drivers after they have parked their car, with route instructions transferred directly onto their smartphone directing them along the last leg of their journey on foot. The Intermodal Route Planning function effectively integrates the car into the local public transport network and provides information on current parking availability at the driver’s destination.
The central information display in the BMW i8 Concept Spyder allows the driver to view the current status of the hybrid system; provides a platform for menu navigation and route guidance; and uses innovative connectivity functions. The car’s power electronics are linked up to intelligent navigation and traffic guidance systems to enable the hybrid drive system to work at maximum efficiency. In this way, information on route profile, speed limits and unavoidable traffic congestion are incorporated into the calculations of the energy management system so that the hybrid system’s operating strategy can be adapted accordingly.
Intelligent connectivity functions open the door to a host of other practical solutions when it comes to preparing the BMW i8 Concept Spyder for its daily workload. One example of this is automatic calendar synchronization with the driver’s smartphone. The system registers upcoming appointments and, when plugged into a power socket, ensures that the battery is topped up overnight so that the car is ready for action with a fully charged battery the following morning.