The Life compartment is made from carbon-fiber reinforced plastic (CFRP), which is said to be as strong as steel but 50 percent lighter. The Drive units are built from aluminum, which BMW says is about 30 percent lighter than steel. On top of those units, traditional plastic is used for the actual body panels. The i8 weighs just 3256 pounds, and because the two drive units are at opposite ends of the vehicle, the i8 has a perfect 50:50 weight balance.
The even weight distribution and multi-link suspension design should conspire to make the i8 handle as well as BMW claims. The front suspension even has special geometry designed to reduce torque steer from the electric motor. The front brake calipers will likely be made from aluminum to cut weight, as regenerative braking and low weight reduce the need for enormous friction brakes. Even though its tires will be relatively narrow for a sports car, BMW engineers assure us the i8 will have "enough" grip for sporty cornering and braking.
To help keep aerodynamic drag as low as possible, the bottom of the i8 is completely flat. Special cut-outs called AirCurtains in the front fascia direct air around the front wheels to reduce turbulence, while the rear decklid and blue rear diffuser are designed to further improve aerodynamic efficiency. Air flows through the Stream Flow channel and under the "floating" taillights, which apparently helps aerodynamics. BMW wouldn't talk about a specific drag coefficient for the i8, but said the number would be "record breaking."
Driver-Focused Interior
BMW elected a driver-focused look for the i8's interior, with a big shift lever sprouting from the center console and flat-screen gauges directly in front of the driver. Occupants sit low in the car, with the hump created by the battery pack running down the middle of the cabin. The i8 is officially a 2+2, so although it has seating for four, the rear seats are extremely cramped. The trunk holds just 5.3 cubic feet of cargo, the same as a Mazda MX-5 roadster.
The center console is also home to the BMW's iDrive controller, parking-brake button, and engine start/stop button. Two 8.8-inch touch-screen displays present information on everything from the radio and navigation systems, to battery charge and electric range. The interior is finished in a mix of Porcelain White plastics, Stream Blue accent trim, and Mocha Brown leather.
There are two special driving modes available in the i8: ECO PRO adjusts the accelerator sensitivity and climate control to improve efficiency, turning the gauges and illuminate blue in the process. Sport mode, as the name suggests, is meant for enthusiastic driving and brings a large, orange-lit digital speedometer to the forefront of the displays.
To keep energy efficiency as high as possible, the i8's navigation system will pre-determine which powertrains to use for different parts of the journey. It might run the gasoline engine on the highway, for instance, then switch to electric power for the final few miles of a trip.
The Future Might Arrive in 2013
The numbers sound like the perfect convergence of performance and eco-mindedness: 0 to 62 mph in 4.6 seconds, 155 mph, and 87 mpg. That assumes that BMW actually builds the car as seen here. The i8 is still a concept car at this point, and its styling will undoubtedly change before it goes on sale in 2013. We also have yet to hear a definite price tag. BMW says the car will return a profit, so given how much technology and materials research went into the i8, it's a fair bet the car will be expensive. We had previously heard the i8 could cost as much as [euro]120,000 (about $171,000).
The BMW i8 will debut publicly at the Frankfurt Motor Show in September, and should go on sale by the end of 2013.