|Taking a Spin in an Electric BMW|
Bradley Berman for The New York Times
THE SILENCE OF THE AMPS: The first all-electric BMW, the ActiveE is an eerily quiet sporty coupe.
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By BRADLEY BERMAN
Published: February 17, 20
FALLING trees may not make a sound when nobody is there to hear — but the sound not coming from the BMW ActiveE poses an equally profound riddle. Even in full sprint, the rear-drive coupe has absolutely no exhaust note.
That’s because the car doesn’t have a tailpipe — or an engine, for that matter. It’s the first 100 percent electric Bimmer, offered to 700 Americans who will help BMW evaluate its electric technology.
I recently spent a week driving one of the first production units around the San Francisco Bay Area, and never stopped marveling at the muted whir, like a jet turbine’s, from the 125-kilowatt electric motor. Which poses the question: Is a BMW any less of an ultimate driving machine if it is silent?
The limited-production ActiveE — only 1,100 will be produced globally — weighs a hefty 4,000 pounds, some 800 pounds more than the BMW 1 Series on which it is based. But the ActiveE carries its bulk with near-gymnastic dexterity. I thoroughly enjoyed tossing the two-ton Teutonic subcompact between the lanes of the Bay Area’s bridges, up and down San Francisco’s steeply pitched streets and along the winding roads of Berkeley’s hills.
Acceleration from a stop to 60 miles per hour comes in an unremarkable 8.5 seconds, but the feel behind the wheel — especially the swift and smooth-as-silk surges from 0 to 30 m.p.h., and from 50 to 80 — was blissful. The steering response is everything you would expect from a BMW.
A well-calibrated suspension helps to counter the extra weight. Dave Buchko, a BMW spokesman, said, “Our engineers are really good at selecting shocks and spring rates that provide well-controlled jounce and rebound.”
Removing the engine and related parts lightened the 1 Series donor car, but installing a 32 kilowatt-hour lithium-ion battery pack added back 992 pounds. The 192 battery cells are crammed all over the place: under the raised “power dome” hood, along the driveshaft tunnel and where the fuel tank used to be.
The added bulk takes a toll on driving range. Yet I managed at least 80 miles of charge every day, even when flogging the system. Driving with more restraint took me closer to 90 miles.
One evening I took a two-hour highway spin, averaging 49 m.p.h. Using the Ecopro setting — which dials back the throttle response, but not to a compromising degree — I went 101 miles with 9 percent of the battery charge remaining, according to the dashboard monitor. Plugged into a 240-volt circuit, the on-board 7.7-kilowatt charger provides an empty-to-full charge in about four hours.
The interior is quintessential BMW, with tasteful materials, austere but useful displays for information like the battery state-of-charge and attention to detail that extends to each meticulous stitch in the leather upholstery.
“It’s a step up from the Mini E,” said Rich Steinberg, BMW’s manager of electric vehicle operations and strategy in the United States. “It’s got leather. It’s got navi. It’s got cruise. It’s got heated seats. It’s got satellite. All the things you’d expect from BMW.”
Mr. Steinberg was referring to the all-electric version of the Mini, the previous test platform, since discontinued, in BMW’s electric-car program. The Mini E was a relatively spartan car with a rough ride and batteries where the backseat might have been. The ActiveE is more refined in all respects, and it uses the same battery, motor and electric drivetrain — developed by BMW in partnership with Bosch and SB LiMotive — that will end up in the company’s full-production electric car, the i3, which is to start trickling into the market late next year.
In the ActiveE, BMW added a liquid-based thermal management system to keep the batteries from becoming too cold or too hot. This helps to prevent the loss of driving range — as much as 40 percent — experienced by Mini E drivers in extremely cold weather.
The most remarkable feature carried over from the Mini E to the ActiveE is the very assertive regenerative braking, which applies strong deceleration as soon as you lift your foot off the accelerator. I drove the ActiveE down Marin Avenue, the steepest street in the Berkeley hills. Without my touching either pedal, the ActiveE slowly glided down the incline to 20 m.p.h. and eased to a crawl — as if in an ultralow “granny gear.” Imagine that same sub-first-gear feel applied on flat roads as soon as you lift your foot, bringing the car from 40 m.p.h. to a stop in about four seconds.
“One-pedal drive is something we’re proud of,” Mr. Steinberg said. “We’re continuing to exploit it not only for the energy reasons, but also because of the driving experience.” BMW estimates that one-pedal driving increases by 20 percent the amount of energy reclaimed when the electric drive motor switches into generator mode and pumps juice into the battery pack.
It took me only a few stops to figure out how to approach a stoplight — lifting my foot off the accelerator at the right time to reach a complete stop at the right spot without touching the brake pedal. On highways or surface roads, I learned how to gently move the accelerator pedal slightly up and down, never taking my foot off, to produce the desired speed — or to find the sweet spot where the car glides along as if coasting.
E.V.’s like the Tesla Roadster have used the single pedal approach, but BMW’s one-pedal E.V. driving will become, I believe, the model for electric car engineering. I’m a convert to the single pedal, and wish the Nissan Leaf — my usual car for daily commutes — drove the same way.
Most E.V. makers aim to give their electric vehicles a driving and braking experience as familiar as possible to drivers of conventional gas-powered cars. The Leaf, even with its impressive quickness, has a wispy feel, whereas the ActiveE operates like a maglev train, hurtling forward, hugging corners and engaging the road (while not burning a drop of petroleum, I might add).
I had ample opportunity to switch back and forth between the ActiveE and my own Leaf. My week with the ActiveE coincided with the week I was to drive my daughter’s car pool to high school. Unfortunately, I was unsuccessful in my latest effort to convince my daughter that her electric-Bimmer-driving dad is cool. The driver seat, slid all the way back to make room for my 6-foot-4 frame, touched the rear cushion, leaving insufficient room in the back seat for her schoolmates.
The batteries in back also trim the trunk space to a barely usable 7 cubic feet. The Leaf, on the other hand, can handle five people along with some gear under the hatch.
So the four students piled into the Leaf each morning. As soon as my parental duties were completed, I rushed back to park and plug in the Nissan and jump into the ActiveE — transforming myself from dad-nerd to electronaut, the name BMW invented for the 700 consumers in a few Northeast and West Coast cities who are putting down $2,250 and paying $499 a month for a two-year lease. The ActiveE is not available for purchase.
The car is a “technology shakedown,” according to Mr. Steinberg, letting BMW gain feedback as it continues development of the i3. That purpose-built electric four-seater — not a conversion — is to go on sale in a few markets by late next year, followed by wider release in 2014.
The company hasn’t officially announced prices or sales goals for the i3, but a year ago Ian Robertson, BMW’s head of global sales and marketing, told Automotive News that the company hoped to sell 30,000 of the futuristic cars in 2014.
Given that the ActiveE is a test platform, it was perhaps not surprising that I encountered a few glitches. Several times, a warning screen told me the shifter couldn’t be moved to “P” — and to take the car to a service center. Another time, a more emphatic “drivetrain malfunction” screen warned, “Stop carefully and turn off vehicle.” I knew from online forums to ignore these as false alarms.
There were also small hiccups in ultra-low-speed driving when various conditions that were hard to identify or replicate — maybe high torque on wet roads or braking-software miscommunications — produced momentary wheel shake. This happened three times during my week of driving; BMW said fixes were expected within days.
As engaging as I found the ActiveE, it is just a step toward the i3, which will have a body mostly of lightweight carbon fiber. The i3 will have more legroom, four doors and subfloor packaging of the batteries — and most important, weigh some 1,300 pounds less than the ActiveE. This will let BMW reduce the size of the battery pack to about 20 kilowatt-hours, from 32, while still providing 100 miles of range. Using the ActiveE’s drivetrain and 170-horsepower motor, the much lighter i3 is likely to be a startling performer.
BMW’s electric efforts won’t end with the i3. “To one degree or another, you’ll see plugs cascade throughout the entire BMW line,” said Mr. Steinberg, the company’s electric vehicle manager.