Prototype Drive
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Ready or not, here i comes.
Regardless of whether the wider driving public has asked for it or not, the electric car is here—and here to stay. Charting the number of new segment entries by model year creates a graph more steeply inclined than a Himalayan ascent. As recently as five years ago, the EPA certified just one electric vehicle for sale in the U.S. In 2013, 10 electrics were in U.S. dealerships, and that number may grow another 50 percent for the 2014 model year.
BMW will roll out its i3 electric sometime during the second quarter of 2014. Different from anything else in the BMW showroom, the i3 is a tall, two-box hatchback with a three-plus-two-door design that mimics that of the discontinued Honda Element. With the front doors open, its rear-hinged half-width rear doors swing out to offer easy entry into the interior, with no fixed B-pillars in the way. The B-pillar supports actually are built into the leading edge of the rear doors.
Totally Modular
The new i3 isn’t bound to conventional architecture, its design hinging on a two-component approach, which includes what are called the Drive module and the Life module. The Drive module is made almost entirely of aluminum. It houses the 170-hp electric motor (located just ahead of the rear axle and offset to the driver’s side); the 450-pound, 96-cell lithium-ion battery; as well as the suspension pieces. No subframes are used—the motor mounts directly to the chassis. It is body-on-frame construction rethought and optimized for weight reduction—truly the first production skateboard-chassis car. There are forged-aluminum control arms locating the front struts, and five weight-optimized steel links at each rear corner. Even the chassis bolts are made of aluminum.
The Life module is the top half of the matched set and it uses as much carbon fiber as the lower half uses aluminum, which is to say plenty. The two modules are bolted and bonded together, creating a stiff structure. The top layer is an unstressed skin made of injection-molded thermoplastic panels which resist dents like the body panels used in Saturn models of the 1990s.
The interior components have been painstakingly lightened, too. Most of the cabin’s panels are made out of hemp-reinforced plastic, complete with exposed fibers, cutting each panel’s weight by roughly 10 percent. The front seats utilize composite shells and have no electric adjustments, while the back seat’s composite pan is reinforced with carbon-fiber trimmings left over from the shell’s production process.
And while we’re on the topic of back seats, the i3’s is rather roomy, although the seat bottom is low to the floor, forcing passengers into a slightly acute knee angle. However, headroom is exceptional, and hip- and shoulder room are decent (thanks in part to two-abreast rear seating). Glass roof panels produce an airy impression.
Specifications
VEHICLE TYPE: mid-motor, rear-wheel-drive, 4-passenger, 3+2-door hatchback
ESTIMATED BASE PRICE: $40,000
MOTOR TYPE: AC permanent-magnet synchronous, 170 hp, 184 lb-ft
TRANSMISSION: 1-speed direct drive
DIMENSIONS:
Wheelbase: 101.2 in
Length: 157.4 in
Width: NA Height: NA
Curb weight (C/D est): 2800 lb
PERFORMANCE (C/D EST):
Zero to 60 mph: 6.9 sec
Standing ¼-mile: 15.8 sec
Top speed: 93 mph
FUEL ECONOMY (C/D EST):
EPA electricity combined: 125 MPGe
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