2011 Automobile of the Year: Chevrolet Volt
By Eric Tingwall
Photography by Jim Fets
Credit: Automobile Magazine (http://www.automobilemag.com)
It wasn't a shoo-in. Quite the opposite, in fact. On its way to becoming Automobile Magazine's 2011 Automobile of the Year, the Chevrolet Volt endured more scrutiny and skepticism than any of the nine other semifinalists. From the unprecedented levels of publicity, we knew the Volt as a green-as-grass image builder, but we also couldn't ignore that it's a car built by a historically inconsistent automaker around unproven technology. The foreign aura is furthered by the fact that the Volt has no obvious competition and no real predecessor. It is genuinely an all-new car, in the most simplistic sense as well as in the greater notion that the Volt is unlike any vehicle we have ever driven. No apologies if we were a bit circumspect.
In its metamorphosis from 2007 concept car to 2011 production car, the Volt has gone through a reckoning. The turbocharged three-cylinder engine and chunky, Camaro-esque styling have been traded for a normally aspirated four-cylinder and a decidedly pedestrian shape. Claims of 0 to 60 mph in 8.5 seconds, a 120-mph top speed, and a total driving range of 640 miles turned out to be the usual concept-car lore. The true numbers are 9.0 seconds, 102 mph, and 350 miles. But the Volt is far deeper than an eco-numbers car. In fact, it's more than just a car. It's an idea. And during the past three years, that idea -- blend the environmental benefits of electric driving with the convenience of gasoline -- didn't change at all.
With a full charge in its 16-kWh lithium-ion battery pack, the Volt delivers 25 to 50 miles of electric driving before firing up a combustion engine for another 300 miles of range fueled by premium gasoline. That engine, the range extender, primarily spins a generator to feed electricity to the motor driving the wheels. It is also capable of providing relatively small amounts of torque to the wheels in parallel with the electric drive motor. The Volt's powertrain hardware isn't exceptional, though. After all, Toyota has sold nearly two million Prius hybrids in the last thirteen years packing two electric motor/generators and a small gas engine under the hood, just like the Volt does. Instead, the intangibles set the Volt apart: control strategies, calibration, computer code, and the philosophy behind it all. Using a planetary gearset and three clutches to connect the two motors and the engine, the Volt powers the wheels in five distinct operating modes. To the driver, though, the Volt has only one mode: effortless.
Although classifying the Volt as a hybrid or an extended-range electric is a matter of semantics, it is unquestionably an electric car from the driver's seat. It launches with whisper-quiet, high-pitched whirs, which are exchanged for the subtle din of wind noise as it reaches speed. A power output of 149 hp won't impress anyone, but 273 lb-ft of torque and a responsive right pedal make it more lively than your typical compact car. Electric propulsion also redefines powertrain refinement. There is no nudge from a transmission swapping cogs or the CVT-induced drone of a strained engine. Power delivery is fluid, acceleration is smooth, and cruising is nearly silent. GM's official line on range -- formerly said to be 40 miles of electric driving -- is now hedged as "25 to 50 miles," due to the profound effect that driving style, exterior temperature, and accessory use have on range. On a suburban route with typical traffic and driving behavior, we covered 40.8 miles in pure electric mode.
The staff had a single word they favored when it comes to describing the gas engine kicking on: imperceptible. The transition is neither heard nor felt. Instead, the only clue is the gas-pump image that replaces the drained battery graphic on the digital instrument cluster. The 1.4-liter engine features dual overhead cams with variable timing, but it's a modest little mill, making just 84 hp at its peak, and it will eventually make itself heard as the revs rise to produce more electricity. It will spin as high as 4800 rpm but spends the majority of its time between 1500 rpm and 3000 rpm. Unless you're listening for it, though, the engine hum disappears behind conversation or the radio. "From the driver's seat, you just drive, with no idea -- and no real need to know -- where the power's coming from and how, exactly, it made its way to the wheels," summarized West Coast editor Jason Cammisa.
When you begin to consider the Volt's other attributes, it's important to remind yourself that the majority of your 41,000 George Washingtons is funding the research, development, and production behind the powertrain and the battery, because the Volt neither rides nor handles like a $40,000 car. Indeed, the suspension is largely lifted from the $16,995 Chevrolet Cruze compact, with a MacPherson strut-type suspension up front and a torsion-beam setup in the rear. The fact that the 435-pound battery pack sits in the central tunnel and under the rear seats is a boon to the center of gravity, but then, adding weight isn't really a recognized technique for improving handling. The chassis dynamics are neither exceptional nor offensive. They simply are. Body control and ride quality are comfortable, and handling is on par with the average compact sedan. The brakes disappoint with a slow and nonlinear pedal, particularly at low speeds. There's also no way to switch off the Volt's stability control.
Our drivers are in unanimous agreement that the design team underdelivered, with a mainstream, generic look. Although you won't hear us pining for the wonky shape of the concept, the Volt's technology, purpose, and capability are deserving of a more progressive design. You can't pin it all on aerodynamics, either, as the coefficient of drag is a good-but-not-great 0.28. "My major gripe about the Volt is the same one I had about the Acura NSX," chided contributing writer Preston Lerner. "This was a chance for the designers to go wild. But, instead, they erred on the side of caution. There are no obvious signposts that this is a car that features breakthrough drivetrain technology. It looks forgettable."
Our flawed hero has internalized some of its shortcomings as well, with the cabin failing to match expectations or price. Although fit quality is up to snuff, the surfaces are aesthetically questionable. The large plastic panels on the upper doors are finished in a solid color or come with a graphic overlay, but either option appears to be an afterthought in the greater styling theme of the cabin. The gloss-white center stack looks to be inspired by an early iPod (note to GM: it's all about aluminum over in Cupertino these days), while the scattered touch-sensitive controls make for a very un-Apple-like user interface. Fortunately, there are more tasteful options, like cream leather and a charcoal center stack. Regardless of how the interior is trimmed, though, climbing into the rear is like getting into an entirely different, surprisingly cheap car. The door panels and the central tunnel are featureless slabs of hard plastic, and rear-seat passengers have to contend with a dearth of legroom and only modest headroom. Blame the battery for the former.
Cherish the lithium-ion battery, too, however, because its 288 cells, along with former vice chairman Bob Lutz's resilience, are why we have the Volt at all. In 2003, Lutz, who had formerly served as CEO of battery-maker Exide, was convinced that battery technology was finally ripe for electric-vehicle duty, but the General Motors decision makers, still wary from the failed EV1 that cost the company dearly in terms of both money and reputation, were reticent. Three years on, the hardheaded Lutz hadn't given up on the extended-range electric, and his crusade was reinvigorated by the dismissive digs of a California start-up company: In publicizing his plans for the electric Roadster, Tesla CEO Elon Musk didn't pass up a single opportunity to slam Detroit. While Tesla did motivate Lutz, the GM product chief had a bigger target than the small start-up with a big mouth. The Volt would also be an opportunity to steal rival Toyota's golden green image, he argued. GM executives finally bit, and in 2006 work on the concept began. The production car was approved shortly after the well-received debut at the 2007 Detroit auto show.
The naysayers embraced the Volt, too. General Motors has worn a target on its back for decades, and a radical gas/electric hybrid was fresh fodder for the critics judging what next product the company shouldn't, couldn't, and wouldn't be able to execute. Then bankruptcy, taxpayer-backed loans, and government ownership happened, and the Volt's poster-child role became even more prominent. It was both villain and hero, depending on who was talking; either an expensive, unsellable science project or the most innovative car Detroit had ever developed. Did you believe? Because the Volt is real, it's here, and it's definitely not hype.
While the hostility toward "Government Motors" won't dissipate anytime soon, the Volt's arrival should at least silence those who insisted that the car couldn't or wouldn't be built. Those who argue it shouldn't exist have yet to drive it. Despite the Volt's imperfections, it takes only a single mile behind the wheel to realize that you are reveling in the experience. Forty, eighty, and 200 miles later, you'll still be marveling at the seamless technology. It is not fast nor is it fun in the typical sense, yet it still has all the brainwashing abilities of a Porsche Cayman. The Volt is unique, but more convincingly, it instills an overwhelming sense that you're driving something significant.
Complex ideas can't be revolutionary until they're accessible enough for mass consumption. There are three separate thermal loops to heat and cool the powertrain components. GM applied for more than 200 patents during the Volt's development. And the advanced battery pack is believed to cost somewhere around $10,000. Yet the Volt packages the game-changing technology in a manner that's nothing short of revolutionary.
Over the past century, the evolution of the automobile has been about more content for less money, faster lap times, more luxury, or better fuel efficiency. The Volt's accomplishments aren't even in the same realm. It won't just change what we drive, but also how we drive. Owners will plug in at night, heat or cool their cabin before they leave the garage, and adopt new driving styles to maximize their electric range. Then, when the battery is depleted, they'll mindlessly motor on, free of the limitations that accompany pure-electric vehicles.
This is the most sophisticated, most important vehicle on the road today. The Volt model could very well be the standard of the future: a smartly sized battery backed by a frugal range extender, whether that's a diesel, a turbine, or a gas engine. In fact, several automakers already have plans to develop similar plug-ins with usable electric driving range and supplemental fossil-fuel power. For being an automotive pioneer, the Chevrolet Volt is the 2011 Automobile of the Year.
The ways the wheels turn
The Chevy Volt is a pure electric, a series hybrid, and a parallel hybrid all rolled into one. The heart of its many modes is an automatic transmission consisting of one planetary gearset and three electronically controlled, hydraulically activated multiplate clutches. This ingenious transmission efficiently blends engine and electric-motor torque to drive the wheels with utmost efficiency. All Volt powertrain components -- two electric motor/generators, the gasoline engine, the aforementioned transmission, and a final-drive differential -- are bolted together in a single unit to save space and weight and to optimize NVH characteristics. To provide 25 to 50 miles of pure-electric operation and 300 or so miles of additional range with the gasoline engine running, the Volt has five distinct operating modes:
1. Battery discharging, acceleration or low-speed cruising: With energy provided from the battery pack, the Volt uses only its larger 149-hp electric motor for cruising below 40 mph or accelerating at any speed. A clutch locks the ring gear of the planetary gearset for a 7.0:1 speed reduction and torque multiplication ratio.
2. Battery discharging, high-speed cruising: Like any energy-conversion device, electric motors are more efficient at certain operating speeds. When the Volt exceeds 40 mph, the clutch holding the ring gear is released. A second clutch engages to connect that ring gear to the smaller of the two electric motors. Now both electric motors draw electricity from the battery pack, and the effective gear ratio is numerically lower, reducing the rpm of the primary drive motor.
3. Battery depleted, acceleration or low-speed cruising: The Volt never empties its battery completely; the gas engine starts when the battery is drained to about thirty percent. A clutch connects the gas engine to the smaller electric generator, which provides electricity to the main electric-drive motor. The ring gear is again fixed for a low overall drive ratio between the motor and the half shafts powering the Volt's front wheels. This series-hybrid regime is used for speeds below 40 mph.
4. Battery depleted, high-speed cruising: The planetary ring gear is again released, shifting the drive motor to a higher gear ratio. The engine continues providing the power to spin the generator, which in turn supplies the drive motor with electric current. In addition, the engine supplies torque to the planetary ring gear through the smaller electric generator; hence, some of the gas/engine power goes to the wheels. Operating in this regime, the Volt is both a series hybrid and a parallel hybrid.
5. Braking: Like all hybrids and electric vehicles, the Volt uses regenerative braking to convert unwanted momentum to electrical energy. When accelerator-pedal pressure is reduced or the brake pedal is applied, the main drive motor temporarily operates as a generator and the electrical current produced restores a portion of the battery's charge. - Eric Tingwall
The Long Road to Volt
The Volt moved from concept to production in a little more than four years -- a remarkably short period for such a complex vehicle. The truth, however, is that it relies on nearly a century of research and development at GM and incorporates contributions from the farthest-flung corners of the company's once-vast industrial empire.
1912: Electric starter replaces crank starter on Cadillacs. It strikes the deathblow to early electric vehicles, which had been marketed on their simplicity. At the same time, it marks one of the first pairings of an electric motor with a gasoline engine in a mainstream car.
1912: GM establishes short-lived Electric Truck Division as part of GMC.
1939: GM's Electro-Motive Division introduces diesel/electric locomotive.
1960s: GM develops electric propulsion system for Apollo lunar module and lunar rover, both of which are powered by silver-zinc batteries.
1964-1966: GM experiments with Electrovairs -- Chevrolet Corvairs with electric motors in back and large silver-zinc batteries in front. GM claims a range of 40 to 80 miles. GM also builds an Electrovan powered by an early hydrogen fuel cell.
1969: GM displays a series of concepts called 512 Series Urban Cars, among which were an electric vehicle and a gas/electric hybrid.
Early1970s: Spurred by the Arab oil embargo, GM again works on a battery/electric Corvair but determines it isn't feasible, largely due to the limits of onboard electronics.
1977-1980: Recession and the gas crunch bring forth Electrovette, a battery-powered Chevette concept. But gas prices collapse once again.
Early 1980s: GM, like many automakers, begins introducing onboard computers for engine management.
1987: Recently acquired Hughes Electronics develops solar-powered Sunraycer.
1991: Inspired by the success of the Sunraycer, Hughes division convinces GM to work on an electric passenger car. The result, the lead-acid battery-powered Impact, debuts at the Los Angeles auto show.
1992: Recession puts a hold on development of production version of Impact, but behind-the-scenes research continues, including work on nickel-metal-hydride batteries.
1996: The Impact reaches production as the lease-only EV1. The lead-acid battery pack provides a range of 70 to 100 miles.
1999: Subsidiary Allison Transmission develops Two-Mode hybrid technology for use in buses.
1999: The EV1 gets nickel-metal-hydride batteries, boosting range to between 100 and 140 miles.
1999: GM works with Toyota on hybrid technology but decides that, with gas hovering around $1 a gallon, there's little potential for consumer sales.
2003: The EV1 program ends. GM repossesses -- and crushes -- cars from lessees. GM publicly focuses on hydrogen fuel-cell technology, but the car-electronics team from Hughes, now incorporated into GM, continues work on battery propulsion.
2006: Filled with Prius envy, GM officially sets to work on a mainstream electric car.
2006: Tesla Motors announces that it will produce an electric sports car, spurring GM vice chairman Bob Lutz to emphatically bless skunk works to cobble together Volt prototypes.
2007: Chevrolet Volt concept car debuts at Detroit auto show. GM promises a production version by 2010.
2008: A scaled-down version of the Two-Mode powertrain, developed with Daimler-Benz, Chrysler, and BMW, debuts in Chevrolet Tahoe and GMC Yukon and is named Automobile Magazine's 2008 Technology of the Year.
2009: Promised Two-Mode version of the Saturn Vue dies with the brand. The Volt's control systems are heavily inspired by learnings from the Two-Mode vehicles.
November 2010: First production Volt rolls off assembly line in Detroit. - David Zenlea
Rising out of the ashes of Poletown
The Volt's assembly plant carries a lot of baggage.
In 1980, GM presented recession-ridden Detroit an offer it couldn't refuse. It would build a new plant to replace two others that it was closing, preserving 6000 jobs along with vital tax revenues, but it needed an appropriate location. The city found a perfect plot along its border with Hamtramck, which was itself reeling from the closure of a Dodge factory. The catch? The land also encompassed much of Poletown, a struggling but proud Polish neighborhood. While most of the 3500 affected residents accepted compensation and left, a vocal minority enlisted the help of Ralph Nader to legally challenge Detroit's right of eminent domain, and a few vowed to physically resist removal. However, the combination of city hall and the world's largest corporation proved impossible to stop, and in July 1981, a wrecking ball crashed into Poletown's Immaculate Conception Church. Today, only an old cemetery hints at what once existed on the 465-acre factory grounds.
The destruction might have been easier to accept had the plant indeed furthered GM's ambitious modernization plan. Instead, expensive robots often malfunctioned and, in one infamous case, ended up painting each other. Even when the bugs had been worked out, mediocrity remained. European bureau chief Georg Kacher visited in 1994 and observed disheveled workers "eating, drinking, and smoking on the job." The finished products -- from the Cadillac Seville to the last Pontiac Bonneville -- mostly underperformed in the marketplace. GM had laid off 2500 workers by 1986, and today the plant employs a sixth of the workforce originally envisioned.
And yet, the scene at the so-called Poletown plant is hardly one of defeat. Following a $336 million investment and several months of employee training, Chevy Volts are now rolling down the same line that builds the hoary but quality-leading Cadillac DTS and Buick Lucerne. The Volt would have to vastly exceed sales expectations to bring the plant up to its capacity of more than 200,000 vehicles per year, but the brightest example of what the "new" GM is capable of may yet outshine this facility's checkered past. - David Zenlea
Credit: Automobile Magazine (http://www.automobilemag.com)
No comments:
Post a Comment