To answer that question--at least preliminarily--we'll have to examine the key features of any electric vehicle aiming for city commuter dollars: range, features, capabilities, and cost.
Using its 22-kWh lithium-ion battery pack and 170-horsepower rear-mounted motor, the rear-drive i3 is good for about 80 to 100 all-electric miles, according to BMW. Add in the 34-horsepower, 650-cc two-cylinder gasoline range extender and that roughly doubles.
The i3's drivetrain setup is similar to that of the Chevrolet Volt, but unlike the Volt, the i3's range-extending gasoline engine isn't capable of driving the wheels directly, even partially--it simply serves as an on-board generator, maintaining the battery's charge.
Despite nearly doubling the i3's range, the gasoline range extender has only a 2.4-gallon capacity--meaning the BMW i3 gets about 33-42 mpg in range-extended mode. Adding the range extender system tacks another 330 pounds on the BMW i3's roughly 2,700-pound curb weight.
Without the range extender (it's an optional add-on) the i3 is about on par with the Nissan Leaf in terms of range. But despite the i3's small footprint, BMW says its advanced construction and design allow it to have the same interior space as a 3-Series.
In that 3-Series-sized space, the i3 packs quite a lot of equipment. Much of it is electric-car kit, including things like Brake Energy Regeneration, which recoups kinetic energy as stored electricity in the battery, and lets the accelerator pedal act as a brake. BMW says the behavior is much like engine braking with a manual-transmission combustion engined car.
Navigation is available, and in addition to guiding you to your planned destination, it can remember your driving style and let you know if your chosen route is too long for the battery charge state, or if it will require a charge before the return trip.
Three trims will be offered, but as this is an electric vehicle, there's a different word for that: "Worlds." The three Worlds are Mega, Giga, and Tera. Mega is standard in the U.S., and includes 19-inch forged wheels with unique aspect-ratio 155/70 tires for low rolling resistance; BMW Navigation; BMW ConnectedDrive with eCall; BMW iRemote; alarm system; 7.4-kW on-board charger; LED headlights, daytime running lights, and tail lights. The cabin of the base Mega World i3 is upholstered in Sensatec and sustainable cloth made from recycled materials. A leather-trimmed steering wheel is also standard.
The Giga World i3 starts with those same features and adds or substitutes unique 19-inch wheels; a leather-wrapped interior; and wool cloth upholstery. A sunroof, satellite radio, and contrast stitching area also included with the Giga World package. The Tera World i3 is the top-line model, getting its own take on the 19-inch wheel look, full-leather interior (the leather is tanned with olive leaves), textile accents, and anthracite floor mats.