Take This Car And PLUG IT By Willie D. Jones Eager hybrid owners can't wait to connect their cars to the power grid A funny thing has happened on what U.S. policy makers thought was going to be the high road to a hydrogen economy. Initiatives aimed at putting hydrogen fuel cell-powered cars on the road by 2020—visualized by President George W. Bush in his 2003 State of the Union address as the centerpiece of his plans to wean the country from fossil fuels—are taking longer than promised. At the time of the speech, hybrid-electric cars, which offer higher fuel efficiency than regular cars because of electric motors that help drive the wheels, were seen in the United States as but a minor detour or way station en route to a world of hydrogen fuel cells. But they suddenly are looking like the main way to go, or even maybe the ultimate destination. Models produced by companies such as Toyota Motor Corp., in Toyota City, Japan, and Honda Motor Co., in Tokyo, are flying out of dealer showrooms. Among those who have been able to purchase hybrids (usually after a two- to six-month wait) are some early adopters—like a group of physics professors at Harvard University, in Cambridge, Mass.—who have made tinkering with hybrids their primary extracurricular activity. Now, a derivative of hybrids that will improve fuel economy even more by maximizing the use of the electric motor is poised to make what is already an undeniably attractive concept downright irresistible. Some of the most eager owners of the Prius, the world's most popular hybrid, have been hacking the cars, swapping their 1.3-kilowatthour battery packs for bigger ones with capacities as large as 9 kWh. The modifications also include the addition of plugs so the new, bigger battery packs can be recharged from wall outlets. The resulting machines, referred to as plug-in hybrids, can be propelled exclusively by their electric motors for, in some cases, more than 30 kilometers without their gasoline engines ever turning on. The factory-built Prius can run on electricity only, but for just a kilometer or two. This group of hackers and other technologists say that in a few years, we could have a car that, after its batteries are topped up overnight via a wall socket, could handle a daily commute using only electrons for fuel—unlike the hybrids on the market now, which still derive all their power from gasoline [see box, "Stretching the Hybrid's Electric Capabilities]." and illustration, "Charging"]. Dramatizing the potential of the plug-in during the Tour de Sol race from 13 to 16 May in Schenectady and Albany, N.Y., a modified Prius equipped with a fully charged 9-kWh lithium-ion battery pack achieved 2.31 liters per 100 km (102 miles per gallon) on a 240-km course. It is representative of the modified hybrids that clean-car promoters and hobbyists have been building, partly for fun, partly to show how wide adoption of plug-ins could lead to dramatically lower gasoline consumption and oil imports. Because of that promise, a strange-bedfellow alliance of environmentalists and security hawks has emerged. They are united by a conviction that the hybrid—not the futuristic fuel cell-driven hydrogen vehicle favored by the Bush administration in its FreedomCar program and other initiatives—is the way to cut both noxious emissions and oil dependence right now. In a manifesto issued last fall in the form of a letter to the U.S. public and then again last March as an open letter to President Bush, a group representing foreign policy intellectuals and advocates of clean energy called for the "technological transformation of the transportation sector through what might be called 'fuel choice.'" The group supports increased reliance on alternative fuels that are domestically produced, such as gasohol and biomass, and on cars such as plug-in hybrids that can draw energy from the grid. "The United States should implement technologies that exist today and are ready for widespread use," the group said in its core statement, "Set America Free." In effect, the report pits a group that includes influential Republicans against a Republican president on the question of whether the country should continue to spend several hundred million dollars a year to promote far-off hydrogen vehicles when it could do more today to accelerate adoption of hybrid-electric and alternative-fuel vehicles. Bold in its Vision, the "Set America Free" report asserted that a plug-in hybrid with a 100-km-range battery could cut fuel consumption by 85 percent and that conventional cars could be converted to run on alternative fuels with the addition of control chips and fuel-line modifications costing less than US $100. Combining advanced plug-in and flexible-fuel features could ultimately yield a vehicle capable of going 100 km on a mere 0.47 liter of gasoline (500 mi/gal), the report claimed. The environmentalists and security-minded luminaries behind the report, such as Frank Gaffney, a senior defense official in Ronald Reagan's administration, and R. James Woolsey, the hawkish director of the U.S. Central Intelligence Agency during President Bill Clinton's first administration, urged Bush to commit $1 billion over the next five years to the establishment of a domestic alternative fuels industry. In addition, they said, the federal government should implement tax credits and other incentives "to encourage rapid production and consumer purchase of advanced vehicles like hybrids, plug-in hybrids, and flexible-fuel vehicles" and to produce "more efficient vehicles across all models." Researchers have shown that battery packs offering an effective electric range of 32 km will yield up to a 50 PERCENT REDUCTION IN PETROLEUM CONSUMPTION Eyeing the draft comprehensive energy bill, which once again is wending its way through the U.S. Congress after being stalled for two years, signers of the report are hoping that its points about hybrids and alternative fuels will make it into the final version. "There's very little doubt in my mind that these sorts of steps will be taken at some point," says Gaffney, founder and president of the Center for Security Policy in Washington, D.C. "The question is [do we take them] after we have realized the very unpleasant national security crisis that we're forecasting, or do we do it in advance of that." Gaffney referred to what the report called a "perfect storm" of circumstances requiring that "we effect over the next four years a dramatic reduction in the quantities of oil imported from unstable and hostile regions of the world." Other report signers include a Reagan national security adviser and a Clinton chief of staff. The "Set America Free" Report is based on two well-founded assumptions. One is that the hydrogen economy cannot be realized for at least a couple of decades, a supposition that emerges clearly from recent reports by organizations such as the National Academy of Sciences, in Washington, D.C., and the American Physical Society, based in College Park, Md. Until basic scientific breakthroughs occur, the reports concluded, the hydrogen vision will do nothing to liberate the United States from energy dependence or improve prospects for bringing down greenhouse gas emissions. The other assumption is that U.S. consumers will be willing, even eager, to pay a premium of a few thousand dollars to get cars that are more fuel efficient and environmentally friendly. Sales of conventional hybrid-electric cars jumped 81 percent in the United States last year and are expected to double this year. These gridindependent (non-plug-in) hybrids cut carbon emissions up to 25 percent and smog precursors by 15 percent. Their gains in fuel efficiency are even more impressive: the Prius gets 4.7 L/100 km (50 mi/gal) on highways, compared with the top-selling Toyota Camry's 7.1 L/100 km (33 mi/gal), and does better yet in stop-and-go traffic, when the battery powers the car more of the time. But make that car a plug-in, with a battery big enough to keep the vehicle in its electric mode for all daily errands and commuting, and the potential fuel savings become truly prodigious. Researchers have shown that battery packs offering an effective all-electric range of 32 km will yield up to a 50 percent reduction in gasoline consumption. And the hope is that in a few years, when advanced batteries like lithium-ion become cheap enough, there will be plug-ins with an effective electric range approaching 100 km. At that point, says Mark S. Duvall, manager of technology development for transportation at the utility-sponsored Electric Power Research Institute (EPRI), in Palo Alto, Calif., the car will run on electricity most of the time. Such a vehicle will use only 10 to 15 percent as much liquid fuel as a conventional vehicle. Duvall points out that there's really not that much difference between the systems in the conventional hybrid cars made by Toyota and Honda, or in Ford's hybrid SUV, and those that would be needed to build a plug-in hybrid. Yet the companies have not made plug-ins available and evidently don't plan to do so anytime soon. To take Toyota, the leader of the pack: "The corporation is committed to hybrid technology, but so far [only for hybrids that] are grid independent," according to David Hermance, executive engineer at the Toyota Technical Center USA Inc., in Torrance, Calif. Why? Hermance says the answer is simple: the cost of the larger battery packs is so high Toyota could never make a profit selling them at a price consumers would be willing to pay. And that's just one hurdle, says the Toyota engineer. Hermance Points Out not only that one Prius-hacking tinkerer paid $15 000 for his lithium-ion battery pack, but that the added batteries make the car heavier—by 68 kilograms in the case of lithium-ion and nearly twice that for lead-acid. Thus, the car's fuel economy is actually worsened when the gasoline engine is running. And there's also the matter of having to replace the battery pack more often during the lifetime of the vehicle because cycling a battery from fully charged to 20 percent charged wears out even advanced batteries. "So you have a higher up-front cost, a heavier vehicle that gets less fuel economy with less performance, and the prospect of replacing the battery during [the car's] life," he says. But the individuals and groups like the nonprofit CalCars—the California Cars Initiative, based in Palo Alto—that have installed bigger battery packs and modified the electronics in the Prius have done so to show that turning the car into a plug-in hybrid is realistic. Ron Gremban, the lead technologist on CalCars' Prius+ project, concedes that the group's modified Prius does not perform as well as it might and costs more than it would if produced by Toyota. But "a company with the resources of a Toyota, Honda, or General Motors could build a more elegant, full-function version for far less money," he believes. How much less is the subject of debate. Toyota's Hermance insists that, barring a spectacular breakthrough in battery chemistry, the cost of nickel-metal hydride batteries will remain around $1100/kWh for the foreseeable future. He concedes that the Prius's nickel-metal hydride battery packs have become significantly cheaper since Toyota began producing the car for the Japanese market in late 1997—power densities have gone up, allowing the car to get the same acceleration with a smaller battery pack. But energy density hasn't really improved, so energy storage remains as expensive as ever. On this point, CalCars' Gremban simply disagrees. He claims that achieving higher power densities is much more expensive than maximizing energy storage, and he observes that with larger battery packs storing much more energy, the higher power densities are not needed. Accordingly, production-volume nickel-metal hydride batteries might cost car companies only on the order of $500/kWh—much closer to the $300/kWh price target, cited by EPRI's Duvall, that will make it practical for a car company to offer a vehicle with a 100-km all-electric range. In any case, plug-in development is already in gear. Duvall reports that his organization and DaimlerChrysler AG, of Stuttgart, Germany, are currently testing four Sprinter vans built at a Daimler facility in Mannheim, Germany. If all goes according to plan, those four vehicles will be the first plug-ins to be tested on U.S. roads. "The project has really developed nicely," says Duvall—so much so that EPRI is negotiating the final details of an alliance of utility and fleet customers to fund and test another 30 prototype vehicles that will hit U.S. roads beginning next year. Asked when we'll see a Daimler plug-in in dealer showrooms, Duvall said, "If [Daimler] makes a production decision to make this vehicle, it would enter the market sometime in 2008 or 2009." Top 10 Tech Cars By John Voelcker Electric cars are back PHOTO: TESLA MOTORS Tesla Roadster About a year ago, the United States was coming off a gasoline price shock, hybrid electric vehicles were the state of the art in production-car technology, and so-called plug-in hybrids were something only a few garage hackers and green extremists did for fun. The world’s largest car company, General Motors Corp., was locked in a boardroom fight while its North American products withered on the vine. Ah, what a difference a year makes. Today, the state of the art has passed beyond hybrids to technologies that seemed dead or ridiculously exotic even a year ago: pure electric-drive cars, including fuel-cell vehicles; and plug-in hybrids, which give the option of charging the hybrid’s batteries directly from a wall socket. Don’t look for such cars in showrooms any time soon, but notice that some pretty specific ideas about how they will enter the market are starting to emerge. And some of those ideas come from an unlikely source: GM itself. But first, a reality check. Nearly 50 million cars and light trucks were sold by major manufacturers worldwide last year. None of those vehicles were pure electrics, and only 350 000—less than 1 percent—were hybrids of one sort or another. By 2025, says Philip Gott, a market forecaster at industry analyst Global Insight, 12 percent of light vehicles sold globally will be hybrids. Another 12 percent, he says, will be diesels. Few analysts will even hazard a guess about when the first pure electrics will show up in the showrooms of major manufacturers. But GM is clearly striving to be the company that puts them there. The auto giant announced several concepts and test fleets last year, all based on a common set of components using electric motors to power the wheels. Even as GM struggled to regain the high ground in tech, it took more than its share of public relations hits. There was the news that it will almost certainly have to cede to Toyota its crown as the world’s largest automaker, either this year or next. It’s a title GM has held for 70 years. The company shed more than 30 000 employees in North America last year (it pledged to reinvest some of the saved cash in technology). Many observers remain skeptical of GM’s goals, pointing to the three decades the company spent aggressively battling any and all regulation in the fields of safety, emissions, and energy usage, while a litany of GM innovations languished in laboratories. There was the company’s romance with hydrogen, for example, exemplified by Hy-wire, GM’s 2002 fuel-cell car. Cars powered by hydrogen fuel cells remain in GM’s vision, but they’ve been recast as a piece of a larger strategy involving electric-drive vehicles. Several other manufacturers have unveiled fuel-cell concept cars, including Honda with its latest FCX, which made our list this year. And there’s more than one way to spin wheels with hydrogen: BMW and Mazda each released roughly 100 production vehicles with the ability to burn hydrogen in their internal-combustion engines. One of the biggest obstacles to hydrogen-powered cars is the lack of global hydrogen production and distribution infrastructure. But the auto industry was jolted by increasing speculation last year that as China builds a network of filling stations, it might possibly use them to distribute hydrogen as well as gasoline—jump-starting the global fuel-cell vehicle industry in a way impossible in more developed markets. Such a strategy would assuage fears, as China goes mobile, of a vast greenhouse gas upsurge. The Chinese middle class is finding out what others learned decades ago: cars are bulwarks of personal freedom and, in the larger picture, of economic growth. Fortunately, cars today are cleaner, safer, more capable, and more reliable than ever. That trend will go on, probably forever. Meanwhile, our collective vision of what constitutes a car is evolving with the technology that makes it go—and feeds our fantasies. 2007 Tesla Roadster A new kind of car from a Silicon Valley start-up It has lithium-ion batteries and comes with a charging cable, just like your cellphone. Unlike your phone, however, it can go from zero to 100 kilometers per hour in less than 4 seconds, pinning you against the back of your seat like a fighter pilot. And it’ll do it with a lot less noise—and for US $70 000 less—than a Ferrari F430. Created by Tesla Motors, a Silicon Valley start-up in San Carlos, the Tesla Roadster is powered by 6831 massmarket lithium-ion batteries and costs about $100 000. Want one? Fine, just put down $75 000 now and wait until summer 2008 to take delivery. The Tesla is based on a design by England’s Lotus, renowned for its small, light sports cars. Tesla's engineers worked closely with Lotus to adapt its Elise platform to electric power, along with substantial reworking to accept Tesla's Lithium-ion battery and distinct styling (in carbon-fiber rather than fiberglass). They also extended the car's wheelbase. The car weighs just 1100 kilograms (2425 pounds), nearly a third of that battery weight. With its 185kilowatt motor, it has a top speed of 210 km/h (130 mph). As with any pure electric car, the key parameters are the batteries’ recharge time, energy density, and useful life. The point of reference is the only recent electric vehicle from a major manufacturer, the late, lamented General Motors EV1. When the EV1 was introduced in 1996, it ran on lead-acid batteries, had a maximum range of 95 km (60 miles), and took up to 12 hours to recharge. The Tesla uses the same lithium-ion batteries found in laptops and digital cameras. Their energy density can be as high as 160 watt-hours per kilogram—or at least four times that of typical lead-acid cells. So the Tesla has a 400-km range and, best of all, it can recharge in as little as 3.5 hours. Unresolved at the moment is the issue of battery life. Laptop batteries usually don’t last the 10 years required of major automotive components. And Tesla has indicated it expects its battery pack’s power to degrade up to 30 percent in as few as five years or 200 000 km. More than a dozen companies are trying to develop lithium-ion batteries in sizes and packages suitable for automotive use. When one of them succeeds, the tactic of lashing together many small cells bolstered by instrumentation to monitor and accommodate the power or thermal variances among them probably will end. Tesla Motors is hardly the only new EV maker these days, though its $40 million in venture funding puts it at the top of the list. Globally, more than two dozen companies are offering electric cars of all different sorts, from drab econo-boxes to supercars like the Tesla Roadster. Meanwhile, as of January, Tesla had sold more than 250 cars—a tidy sum at $100 000 each. The first cars are supposed to be delivered in September, if crash-test analyses and other U.S. government-certification requirements go smoothly. Tesla also has plans for a second car, a sporty four-seat sedan code-named White Star. The company hopes to launch that car by 2010, at a price of $50 000. To do so, it has set up an engineering center in Rochester Hills, Mich., and plans to staff it with more than 50 engineers. Honda FCX / Concept Can a fuel-cell car be sexy? If you want one, you’ll have to wait until 2018 at least, Honda says. But still, its latest "FCX concept car takes hydrogen fuel-cell power trains into a new, sleeker realm. It’s a radical, stylish departure from the previous FCX’s upright, slab-sided hatchback design. Honda revealed its new FCX this past summer, around the same time GM previewed its Chevrolet Sequel fuel-cell vehicle. But the two cars couldn’t be more different. The Sequel is a conventionally attractive sport-utility vehicle, but the FCX is a low, four-door, five-passenger sedan. It would look right at home on the Autobahn, although its maximum speed of 160 kilometers per hour (100 miles per hour) wouldn’t win it many friends in the left lane. It is powered by the company’s third-generation fuel cell, which is 20 percent smaller and 30 percent lighter, and at 100 kilowatts, 14 kilowatts more powerful. The new V (for vertical) Flow stack stands upright, and can be packaged in what used to be called a “transmission tunnel” between the seats, lowering the center of gravity and doing away with the characteristic tall, upright design of most previous fuel-cell vehicles. More important, the design helps eliminate one of the biggest obstacles to mainstream use of fuel-cell cars: the cost and complexity of the systems needed to let the cells withstand subfreezing temperatures when they’re not running. Water is a by-product of the reaction that liberates electrical energy in a fuel cell. But any water remaining in the cells’ stack, where the reaction occurs, would cause damage if it froze there. In Honda’s vertical-flow design, gravity helps drain that water—improving performance and reducing the power needed to pump the stack dry every time the car is turned off. According to Honda, the system works so well that the car can start at temperatures as low as –20 °C. With a smaller and lighter 95-kW drive motor, the new FCX’s complete power system is 180 kilograms lighter and almost 40 percent smaller than its predecessor’s. Hydrogen is stored in a 171-liter tank at a pressure of 350 atmospheres, giving the car a range of 435 km (270 miles), Honda says. Honda plans to put the car into very limited production in Japan next year. Still, it’s a step forward: virtually all fuel-cell cars built so far have gone into carefully maintained and sheltered fleets at utility companies, for example. But Honda says it is considering leasing the cars for US $600 or $700 a month to interested private citizens, to get real-world feedback on how the new FCX drives, rides, and performs. 2008 GMC Yukon Two-Mode Hybrid A hybrid heavy hauler GMC’s Yukon is a strapping 2500 kilograms unloaded. In other words, it ain’t no Prius. And yet, Yukons fitted with GM’s new two-mode hybrid system use essentially the same principle to reduce energy consumption as Toyota’s celebrity-friendly it-car. An electric drive can power the vehicle, by itself or together with the combustion engine. The battery that powers the motor is charged by the engine and also through regenerative braking. Being as big as it is, though, the Yukon outdoes other hybrids by having two electric drive motors, each capable of 40 kilowatts sustained. A single motor with enough torque to move such a mass couldn’t be accommodated inside the truck. So GM’s engineers, who led a design effort that later included engineers from DaimlerChrysler and BMW as well, used a pair of electric motors—a system GM had previously put into production for its hybrid transit buses. As in the Prius, the Yukon’s motors are actually motor/generators that can produce torque when fed with electricity—or vice versa. The size of the system was constrained by the need to fit it into the same space as the company’s 6-speed automatic transmission. Inside an aluminum casing are packed not only four fixed gears but (from front to rear) a “planetary” gear set and electric motor, a clutch, a second planetary gear set and motor, and then a final clutch and gear set. In each planetary gear set, a central gear (the “sun”) is spun by the engine or electric motor. The sun is surrounded by planet gears that are in turn surrounded by a ring gear, which drives or is driven by another motor. By varying the speed at which the planet gears spin, you also change the power split between the torque on the sun and that on the ring gear. Being able to split the power arbitrarily like that lets you channel just the right amount of the engine’s power to the wheels; the rest is devoted to charging the batteries. The “two modes” of GM’s system refers to the different mixes of electric-motor and combustion-engine torque. The first, or input-split, mode is for low-speed and light-load applications from launch through second gear. As in existing single-mode hybrid systems, a planetary gear set splits engine power between the wheels and one of the two electric motors. Acting as a generator, this motor charges the battery, which powers the other motor, which drives the wheels as well. In this mode, the engine-control system alternates among electric-only, engine/electric, and engine-only drive, choosing the option that provides the best performance with the lowest fuel consumption. From rest, energy from the 300-volt nickel-metal-hydride batteries powers the drive motor, which is quickly supplemented by torque from the engine. The second, or compound-split, mode is for high speeds and heavy loads. It provides electric assist in the third and fourth gears. Here, both electric motors can receive torque from the engine and power from the battery. The second and third planetary gear sets not only split the engine power among the drive wheels and the electric motors, they can multiply all torque to deliver maximum power to the wheels. Controlling it all are microprocessors. In fact, according to chief engineer Tim Crewe, 70 percent of the total effort involved in designing and testing the system went toward control logic. That logic analyzes hundreds of inputs every 10 milliseconds, including vehicle load, engine operations, battery parameters, and the temperatures in the high-voltage electric components. Depending on vehicle speed and power requirements, one motor-generator may assist the engine, or provide regenerative braking, with the other shut down for greater efficiency. Or both motors can provide boost or braking simultaneously. And the combination of planetary gear sets and electric motors smooths the shifting among modes, so that engine speed can stay constant even as it varies the electric power delivered to the battery or drive wheels. When coupled with cylinder deactivation, the two-mode hybrid system is expected to improve overall fuel economy by 25 percent, to 10 or 11 liters per 100 kilometers (about 22 miles per gallon). For comparison, the standard GMC Yukon gets 15 to 16 L/100 km (roughly 15 mpg) in the city and 11 to 12 L/100 km (20 mpg) on the highway, according to the U.S. Environmental Protection Agency. 2007 Fiat Siena Tetrafuel Auto omnivore Stand on a street corner in any middle-class suburb in Brazil and well over half the cars whizzing by will be flexfuel vehicles capable of burning various mixtures of gasoline and ethanol. Among Brazil’s many flex-fuel cars, a version of the Fiat Siena stands out because it runs on any blend of ethanol and gasoline, and also on pure natural gas as well. It burns the natural gas first because it’s Brazil’s cheapest car fuel. The Siena stores the liquid fuel in a 48-liter tank and the natural gas in two 6.5-cubic-meter cylinders in the trunk. The 1.4-L engine has two sets of injectors, one for liquid fuel and a second for natural gas. But those are the engine’s only major hardware modifications. The engine-control unit (ECU) is the same as the one on ordinary Sienas. It just runs more sophisticated software. The car’s existing sensors measure the airflow into cylinders, the engine speed and load, and the specific fuel being sent to the engine. The data are fed to the ECU, which uses them to optimize fuel injection and spark timing. Most important, the ECU uses data from the sensor that monitors oxygen in the exhaust to vary the air-fuel mix continuously until that sensor detects no oxygen remaining in the exhaust, indicating complete combustion. 2007 Volkswagen Golf GT TSI Recipe for fun: take a turbo and add a blower Powerful small-displacement engines have always been a European specialty. But even in Europe, an engine that puts out more than 75 kilowatts (100 horsepower) per liter of displacement is notable. So one that gets 125 kW (168 hp) and 240 newton meters of torque from 1.4 liters is quite an achievement. Throw in fuel consumption of 7.2 liters per 100 kilometers (33 miles per gallon), and you’ve really got something to cheer about. So let’s hear it for Volkswagen’s Golf GT with the TSI Twincharger engine. VW’s goal was to reduce carbon dioxide emissions while maintaining power, torque, and driving characteristics in an engine that could be produced in high volumes for a variety of vehicles. The resulting engine delivers the highest specific power of any mass-produced 4cylinder, and the same torque as a 2.3-L engine while using 20 percent less fuel. VW’s engineers opted for the conventional approach to maximizing kilowatts per liter: start with small displacement, and coax out every possible kilowatt. To do this, their unusual trick was to use both a supercharger and a turbocharger. Each is essentially a pump that pushes more air into the cylinder, allowing more fuel to be used, thereby increasing an engine’s power. But a supercharger is basically an air pump driven by gears or a belt from the engine’s crankshaft, while a turbocharger is a small turbine spun by the force of escaping exhaust gases. Because it’s driven off the crankshaft, a supercharger can supply additional air to the combustion process even at low engine speed. On the other hand, a turbo has to “spool up” to its operating speed, which happens only when the engine is running fast enough to generate significant exhaust pressure to spin it. The delay between a driver accelerating and the turbo boost coming on is called “turbo lag.” VW’s supercharger compensates for that lag. Below 2400 revolutions per minute, the supercharger can increase the pressure of the air provided to the combustion process by up to 150 kilopascals (about 1.5 atmospheres). Under acceleration from 2400 to 3500 rpm, the supercharger stays engaged while the turbo spools up. Once the turbo nears its maximum boost of 250 kilopascals (2.5 atmospheres), a bypass flap switches the air supply from the supercharger to the turbo. The integration of the two provides high torque from 1750 rpm to 4500 rpm. Chevrolet Volt / Concept GM's vision of an electric-drive future Hybrid-electric vehicles have been available for a decade now. And within a few years, so?called plug-in hybrids will offer beefier batteries that can be recharged from a wall socket, as well as by the vehicles internal-combustion engine. But both variants are still adapted from the same design handed down during a century of mechanically driven cars, in which the engines torque is transferred mechanically to the wheels. A more radical design is the series hybrid electric car—driven by one or more electric motors powered by batteries that can be recharged by the combustion engine. In the series configuration, the combustion engine cannot drive the wheels directly; it switches on, only as needed, to run a backup generator that recharges the batteries on trips that exceed the cars all-electric range. The Chevrolet Volt, which stole the show at Detroits North American International Auto Show in January, is the first-ever series hybrid concept vehicle shown by a major carmaker. Its 1-liter, 3-cylinder turbocharged engine runs an onboard 53-kilowatt generator that recharges a 16-kilowatt-hour lithium-ion battery made up of 80 4-volt cells. That battery powers the car through a 120-kW electric motor delivering 320newton meters of peak torque, giving an all-electric range estimated at 65 kilometers (about 40miles). The plug-in recharge time likely will be 6.5 hours or less. And the 45-L gasoline tank gives almost 1000 km between refuelings. On paper, anyway. We dont have a battery pack yet for the concept, acknowledges Tony Posawatz, the vehicle line director, who confirmed that the car shown in Detroit doesnt yet run—so its range has been estimated from lab tests. Among other qualifications for automotive use, lithium-ion battery packs must last 10 years or longer through more than 4000 full charge-discharge cycles. The Volt is the first of several concepts that are expected to use what GM calls its E-flex platform for electrically driven vehicles. Starting around 2010, GM plans to build a variety of subcompact vehicles the size of an Opel Astra on a basic architecture that accommodates E-flex components. Some will have combustion engines, some are likely to be parallel hybrids with plug-in capability, and others may be serial hybrids like the Volt. GMs announcement that it would produce cars using E-flex changed the Volt from just another shiny concept to a possible precursor of a truly radical shift in drive technology. During the Volts unveiling, Robert A. Lutz, GMs vice chairman for product development, was clear: GM intends to sell cars powered by electricity. But, understandably, the company wont commit to a date for doing so until it can get sufficiently powerful and durable lithium-ion batteries for automotive use. 2007 Subaru Outback 2.5XT A sensible car acquires multiple personalities Subaru has always been a Jekyll-and-Hyde company. Its sensible all-wheel-drive station wagons sit in the same showrooms as their unruly alter egos, such as the fast, road-hugging Impreza WRX sedans, developed over many years of punishing off-road rallies. Now Subaru has introduced technology to let drivers choose—sensible or wicked?—by twisting a dial on the console. The Subaru Intelligent Drive (SI-Drive) system lets drivers select one of three modes: Intelligent, Sport, or Sport Sharp. It comes standard on three 2007 models—one of them the Outback 2.5XT with automatic transmission—and more are due next year. The turbocharged 2.5-liter double-overhead-cam engine in the 2.5XT—in which the cylinders are horizontally opposed, like a Porsche’s, to lower the center of gravity—produces 181 kilowatts (243 horsepower) and a rousing 327 newton meters (241 foot-pounds) of torque. As you change SI-Drive modes, the system’s control software revises settings for the engine control, automatictransmission shift points, and throttle response. In Intelligent mode, the system limits engine torque to 309 Nm, thereby cutting maximum power by roughly 20 percent. It also makes throttle response smoother and more gradual, improving the fuel mileage by up to 10 percent, Subaru says. The Sport mode sharpens throttle response to favor acceleration and power over fuel efficiency. This mode is best for freeway and suburban driving and in hilly terrain, Subaru says. The Sport Sharp mode emphasizes instantaneous power delivery. It’s useful for passing. Remapped shift points hold the car in its lower gears longer, improving acceleration by more than 50 percent compared with Intelligent mode, Subaru says, and mimicking the wild-child behavior of the WRX. The idea of a single engine with multiple personalities had long been the dream of Toshio Masuda, Subaru’s project general manager for the Legacy Outback line. Despite skepticism that such a system was possible, one of his engineers built a prototype of what would become the SI-Drive and installed it in a test “mule.” That car gradually won management over to the idea. The team’s challenge lay in the fact that offering three performance profiles required three times as much software development and testing. 2008 Audi R8 LED lights hit the road The R8, Audi’s first excursion into supercar territory, is projected to cost roughly US $130 000 when it hits showrooms this year. If the current crop of starter supercars leaves you underwhelmed, your ship may be about to come in. The R8 is stuffed with advanced technology, including an aluminum space frame, a direct-injection midmounted V8, and a 465-watt 12-speaker sound system. It also has shock absorbers filled with fluid whose viscosity is varied electromagnetically, as in the Cadillac XLR and SRX. All those technologies have appeared in other cars, but not all together in one car. And the stylish, two-seat R8 has something that sets it apart in its category: light-emitting diodes for its daytime running lights. LEDs offer many advantages as automotive lamps, including low power and long life. The automotive-lighting company Hella quotes just 10 W for a pair of LED running lights, against as much as 150 W for standard, incandescent ones. LEDs also last up to 50 000 hours—which translates to 100 years of headlight use for an average car. And they’re small enough to give stylists great freedom over front-end design: designers can cluster or scatter single LED lamps as their sketches require. The only problem is cost: up to $1000 per pair if you have to replace them. That’s roughly 10 times as much as the high-intensity discharge lamps, which cast a bluish light, used on upscale cars today. So for the moment, LED running lights are limited to just a few high-end Audis: the R8 and the A8, S6, and S8. The racy R8, however, goes its siblings one better by also using LEDs to illuminate its 4.2-liter, 309-kilowatt, high-revving V8, which is visible through a window behind the seats. The R8’s lights are produced by Osram Opto Semiconductors, in San Jose. Each running lamp has 12 separate LED spotlights arranged in a sinuous curve under the pod containing the high beam and turn signal. Each of the LEDs provides 18 lumens at 140 milliamperes. Meanwhile, Audi and Lexus are competing to be the first to use LEDs as headlights in a production car. Lexus probably will win the race, as its LS600h—the ultraluxurious hybrid-electric flagship of the LS line—is expected to hit showrooms any day now. The Lexus designers stayed with a conventional headlight shape—which holds highintensity discharge lamps in other LS models (it was shaped to evoke Baccarat crystal). But Audi promises to offer full LED headlamps as an option for the R8 by the end of this year. 2008 BMW 5-Series Regenerative braking in a nonhybrid For 40 years, engineers from the Bavarian Motor Works have ingeniously applied technology to the pursuit of a single goal: superb handling and performance. But nowadays, not even BMW can ignore calls for cars that consume less, emit less, and tread more gently on the planet. The company has not announced a hybrid, though it has partnered with GM and Daimler Chrysler in their twomode hybrid project [see “2008 GMC Yukon Two-Mode Hybrid”]. And now, on its revised 5-Series sports sedans, BMW has introduced regenerative braking—the first time such a system has been used on a nonhybrid car. The company’s Brake Energy Regeneration system grew out of an intelligent alternator control project shown at last year’s Paris Auto Show. The core idea is to change the times at which the alternator charges the battery. In a conventional car, the alternator generates power continuously, regardless of other loads on the engine. But in the new 5-Series cars, it is engaged to generate power only when the car decelerates. At other times, when the car is cruising or accelerating, it merely freewheels. With the alternator no longer sapping power—a phenomenon known as alternator drag—the engine needs to work slightly less hard to move the car, cutting fuel consumption. The alternator itself has not changed; BMW has simply inserted an electronically controlled clutch that engages to let it charge only when the car decelerates. The power to drive all the car’s electric components—as much as 3.5 kilowatts in the average midsize car these days—is supplied by a somewhat more powerful battery. BMW won’t release exact figures, but it does say that it uses glass-mat technology, which separates the battery’s plates with saturated absorbent glass—boron silicate— rather than the usual gel or liquid electrolyte. The acid electrolyte is held in the microfibers between layers of lead, improving its energy storage during frequent charge/discharge cycles, compared with standard lead-acid batteries. Those ordinary batteries convert up to 20 percent of electrical energy to heat during charging, against as little as 4 percent for glass-mat designs. Alternator drag is found in almost every vehicle sold today, so its impact may seem insignificant. But in the European Union driving cycle, which is used to measure fuel consumption for cars sold within that market, BMW’s revised alternator system reduced energy consumption by roughly 3 percent. 2007 Chrysler Sebring Nav system + DVD player + iPod + phone + hard drive = integration If you’ve bought a new car recently, chances are that it can accommodate most of the entertainment media, formats, and compression algorithms you probably now enjoy: AM, FM, and satellite radio; CD; DVD; MP3. But the challenge of accessing all those options may have left you resignedly listening to the drone of news radio. Chrysler feels your pain. A new, US $1700 option on this year’s Sebring sedan bundles players for all those media, plus a cellphone and navigation system, into a single dash-mounted entertainment setup called My Gig. The system, developed with stereo maker Harman/Kardon, features a single, consistent user interface to operate them all. In the My Gig–equipped Sebring, the disc player can play music or show movies to backseat passengers from a 7inch display at the rear of the console between the front seats or—if the car is parked—on a 6.5-inch in-dash display. The music, video, and navigation functions can all be controlled by voice commands (in English, Spanish, or French) or through a touch screen. The system integrates Bluetooth hands-free mobile calling, and it can record voice memos. The heart of the My Gig system is its ruggedized hard drive that holds navigation data and up to 1600 MP3 or Windows Media Audio files, as well as eight photos and up to 32 address-book names. It is one of the first carbased systems that lets you rip CD tracks into MP3 format and store them on the hard drive. MP3-savvy readers may wonder how the system, without an Internet connection, can fetch the artist, title, and other track information for a CD. Glad you asked. Included within the system’s 1 GB of software is the Gracenote lookup engine to locate information for roughly a million CDs that Gracenote believes North American users may play. Chrysler hadn’t decided at press time whether to charge users for quarterly updates at the dealer. This article was updated 10 April 2007. About the Author JOHN VOELCKER has written about automotive technology and other topics for 20 years. He covered software and microprocessor design for IEEE Spectrum from 1985 to 1990. Made-to-Measure Mass Transit By Willie D. Jones Driverless cars aim to give each passenger a customized ride IMAGE:ADVANCED TRANSPORT SYSTEMS ON TRACK: One of the automated vehicles that will shuttle people around London's Heathrow Airport. A snaking array of steel pillars outside the newly renovated Terminal 5 at London's Heathrow Airport will, by the end of next year, hold up a guideway upon which little automated electric vehicles will shuttle passengers and airport workers back and forth between the terminal and a distant parking lot. In doing so, the pillars will also be supporting a transportation movement decades in the making. The project—dubbed ULTra (Ultra Light Transport) and designed and built by Advanced Transport Systems, of Bristol, England—is but one example of a mode of quasi-public transportation known as personal rapid transit, or PRT. According to PRT purists—including the board of the Advanced Transit Association, which advocates the use of technology to solve transportation problems—this label can be applied to transit systems that have all the following characteristics: fully automated vehicles that run on a reserved guideway; small vehicles that can, like taxis, provide exclusive use for small groups or even a single passenger; nonstop service using the most direct route available; off-line way stations; and on-demand access to vehicles instead of fixed schedules [see photo, “At Your Service”]. As with ice cream, the basic ingredients that PRT systems have in common impose few limits on variety. When ULTra is completed in late 2008, it will comprise 3.9 kilometers of paths populated with battery-powered, four-seat jitneys capable of speeds up to 40 kilometers per hour and able to follow each other with a 6-second separation between one car's tail and the next one's front bumper. ULTra's cars will run on rubber tires; other proposed systems will anchor the cars on rails above the guideways or suspend them from the dedicated paths. Because this will be the first true PRT system to go into passenger service, the ULTra project is a test case for whether all the claims made by PRT proponents are true. Proponents maintain that PRT can be an important complement to existing mass-transit systems such as light rail, commuter trains, and buses. PRT advocates also predict that personal rapid transit systems will entice people to drive less, reducing the congestion, energy consumption, and environmental impact from passenger car traffic. If ULTra can be completed on time, on budget, and operate as designed close to 100 percent of the time, it could represent a tipping point. Once Heathrow has set the example, other municipalities might jump on the bandwagon. “There's a long, long line of cities, and they're all really keen on being second,” says Martin Lowson, Advanced Transport's CEO. IMAGE:ADVANCED TRANSPORT SYSTEMS AT YOUR SERVICE:Advanced Transport’s four-seat jitneys will provide private, nonstop, on-demand service along exclusive guideways. But to this point, a host of variations on the theme have always fallen short when transit authorities have looked to expand their operations. For example, the city of Irvine, Calif., reported earlier this year that PRT is no longer under consideration for a transit extension that would serve a new park being built on the grounds of a shuttered U.S. Navy air base. Some observers say that PRT's inability to gain any footing is purely political. “The rail lobby has exhibited a lot of influence over these types of decisions,” says Robert Hendershot, who runs a PRT-like system that connects scattered parts of the University of West Virginia's campus with the city of Morgantown's central business district. “The technology has really proven itself,” he insists, adding that, “Honestly, I thought the tipping point would have occurred 10 or 15 years ago.” But Morgantown's 30 year track record doesn't sway decision makers because it isn't considered a true PRT system. It features 20-passenger cars and frequently operates on a scheduled, station-tostation basis during peak hours rather than on demand. Also getting in the way is the memory of one or two past PRT projects that failed spectacularly and others that went away quietly after funds dried up. One oft-cited example is PRT2000, a Raytheon-backed transit system that was to be installed just outside Chicago during the 1990s. Raytheon terminated the project when the company discovered that changes from the original design conceived by University of Minnesota engineering professor J. Edward Anderson had raised the construction costs to nearly US $30 million per kilometer. (The rights to Anderson's design, which subsequently reverted to the university, were later sold to a Fridley, Minn., start-up called Taxi2000.) Asked about these failures and what sets Advanced Transport's effort apart, Martin Lowson, the company's CEO, gave several reasons for optimism. “Early attempts happened in the 1960s and 1970s,” he says. “Technology has advanced a long way since then—not only in capability but in cost. Components that would have cost tens of thousands of dollars 20 years ago you can now get for less than a thousand.” Still, the company's mantra has been “no more technology than necessary.” Lowson says Advanced Transport takes pride in the fact that ULTra will use mostly off-the-shelf equipment, including a 48-volt lead-acid battery for propulsion power. It will also have an anticollision system modeled on the one used by railways for decades, in which the cars communicate their positions on the track via inductive loops in the tracks instead of a more expensive wireless link. The results, he says, are lower start-up and operational costs as well as greater reliability. He notes, for example, that in two years of tests at the company's 1-kilometer track in Cardiff, Wales, the system hasn't failed. Critics, however, remain unconvinced. For this limited application, covering one part of Heathrow, personal rapid transit might work, says Vukan R. Vuchic, a professor of transportation engineering at the University of Pennsylvania, in Philadelphia. But he doubts that the system will be scalable—not even to the extent that it will be able to take over from shuttle buses the entire task of ferrying people across all of the airport's grounds. “I don't see what kind of function personal rapid transit will serve, because it combines the negative features of cars and subways: expensive guideways [for subways] and low capacity [of cars].” Mike Lester, chief operating officer at Taxi2000, explains that PRT was never meant to replace trains and buses but to extend their reaches in ways that are less expensive and more environmentally friendly. “You'll never hear me say that we shouldn't have light rail or subways,” Lester insists. He and Advanced Transport's Lowson say that one of the tough parts of waking people up to the benefits of PRT has been managing expectations. “There are a lot of people who are skeptical about it, which is an entirely reasonable point of view to take when it comes to new technology,” says Lowson. “We have a low-speed system with modest capacity, and we're very confident that we can do an effective job delivering that service in a way that is reliable and ranks high in terms of passenger service.” Loser: Grounded By Sandra Upson No happy landings for latest twist on sci-fi staple ILLUSTRATION: JASON LEE When is a flying car not a flying car? When it’s a Transition and when its maker, Terrafugia, insists on calling it a “roadable aircraft.” Think of it as an airplane prototype suited for limited operation on land, the Cambridge, Mass., company says. In other words, do your best to imagine an eccentric flying machine that only occasionally moonlights as a car. Like platform shoes and plastic flamingos, the convertible car–airplane concept just won’t go away. During the past century, dozens of models have emerged, including one capable of vertical takeoff and one with bolted-on wings that pilots detached and carted along in a trailer. None have risen above the status of historical footnote. Here’s the problem: it has proven to be virtually impossible to craft a light, agile plane that also handles well on the road. Basically, a car is safer and more stable when it’s heavier, while a plane flies better when it’s lightweight. So far, Terrafugia has completed a detailed design and is now trying to raise funds to build a prototype by 2008. To hide the fact that the Transition is a flimsy car and a feeble plane, Terrafugia designed the vehicle to weigh just under 600 kilograms, the cutoff for the U.S. Federal Aviation Administration’s new light-sport aircraft class. Such planes are to be flown only in good weather at low altitudes and relatively slow speeds, and Terrafugia hopes that in this class, the Transition’s limitations won’t stand out. In Terrafugia’s simulations, the Transition looks like a stubby little plane affixed to a four-wheel platform. At the push of a button, the wings fold and tuck in alongside the body, sort of like the wings of a perched eagle. With bumpers on both ends, the car-shaped body would cause the Transition to experience more drag and fly at slightly lower speeds than other light-sport aircraft. Unlike those on normal planes, its wings would be flat on the bottom so that they could fold completely—which reduces the Transition’s aerodynamic performance. What the Experts Say GORDON BELL: If he builds one, it may be good training. No harm done. Every decade, someone should try to build one. As a car, however, the Transition fares far worse. Although 600 kg isn’t unreasonable for a light prop plane, it is decidedly wispy for a car. For comparison, a Mini Cooper, one of the smallest four-seat cars that is widely available in North America, weighs almost twice that much. A strong gust of wind could cause the Transition to fishtail. To make things worse, its folded wings would create mammoth blind spots on a vehicle the length of a large pickup truck and would be easy targets for fender benders. Terrafugia says that in car mode, the Transition would typically be used only to drive between home and airport. Still, that might be enough to exasperate its owners. “We have become very demanding when it comes to safety issues in cars,” says C.P. (“Case”) van Dam, a professor of mechanical and aeronautical engineering at the University of California at Davis. “We expect comfort and high performance.” The same expectations have shaped pilots’ preferences in small aircraft, van Dam notes, adding, “If you end up compromising in both areas, do you really satisfy a large enough group of people?” Amateur pilots buy approximately 1000 small aircraft each year, according to Richard Golaszewski, executive vice president of GRA, an aviation consultancy in Jenkintown, Pa. Carl Dietrich, Terrafugia’s chief executive, estimates that the market is slightly larger and says he is confident he will sell “a couple hundred” Transitions annually in each of the next few years—which would be quite an accomplishment for an unknown, untested design team. Priced at US $148 000, the Transition falls significantly outside the $50 000 to $100 000 price range of new lightsport aircraft. By opting for an $80 000 Rans S7, for example, a pilot could, for the same amount of money, choose to spend the remaining $68 000 on cab rides, rentals, or a new superloaded Chevy Corvette. Dietrich, who is working on a Ph.D. in aeronautics and astronautics at MIT, won the 2006 Lemelson-MIT Student Prize for the Transition’s design. Using the $30 000 award, Dietrich launched Terrafugia that spring, with the hope that his vehicle would make noncommercial air travel significantly easier. Dietrich is not alone in his belief that the airspace over the world’s sprawling metropolises is clogged, with little room for growth. Many say that regional airports provide a convenient outlet and that the main obstacle impeding their use is the trouble of getting a pilot to and from the airport. According to Dietrich, only one third of the 5000 general-aviation airports in the United States have taxi or car-rental facilities nearby. With the Transition, Terrafugia’s engineers dream that personal air travel will finally become mainstream. “Comparing two different light-sport aircraft, one standard and the Transition, there’s a lot of draw to an airplane you can keep in your garage,” Dietrich says. Even if Terrafugia meets its goals, the air expressways of Back to the Future and “The Jetsons” will remain the stuff of daydreams. Boeing and NASA have independently analyzed the feasibility of personal air vehicles and each concluded that a wider problem hinders individual air travel: the absence of support structures to make increased traffic safe and reliable. “After an initial look at designing a vehicle, we decided we were missing the big picture,” says Lynne Wenberg, a senior manager at Boeing’s Phantom Works research division in Seattle. More traffic at small airports necessitates more air traffic management, control towers, and systems to help lower-skilled pilots land in bad weather. NASA aviation expert Bruce Holmes argues that small airports would have to undergo a massive, government-supported update. “This is really not going to be a one-company development,” Holmes says. At the moment, however, the U.S. National Highway Traffic Safety Administration holds sway over Terrafugia’s future. If the agency decides the Transition is sufficiently carlike, Terrafugia will have to comply with crashworthiness standards that would add weight to the car and further complicate the design, potentially dooming it. Rather than abandon the light-sport aircraft idea, Dietrich says he would resort to a three-wheeled version, to be classified as a motorcycle, which has looser safety requirements. Some aircraft designers, including NASA’s Holmes, actually prefer the idea of a flying tricycle, because it is less likely to become mired in traffic safety restrictions. But Dietrich is reluctant to move in that direction, hoping to keep the vehicle in a more familiar shape. For the time being, the flying car stays tethered to the shop, a clunky compromise whose time may never come. Hard Drive By Willie D. Jones Robotic cars impress in rough road race Will cars ever be capable of driving themselves? Someday. But the computer software packages designed to control steering, braking, and throttle are in the midst of a trial-and-error learning stage all too reminiscent of a teenager's first experience behind the wheel. Only after some unnerving instruction—and perhaps a dented bumper or two—are they good enough to go solo. On 9 October, computer algorithms showed that cars might just be ready to take the wheel without human chaperones. That was the day that four autonomous vehicles completed a 211-kilometer racecourse stretching through Nevada's Mojave Desert in less than 10 hours, as required by the rules. The autos avoided boulders and other obstacles, traversed bridges, and maneuvered through hairpin turns on mountain switchbacks as they vied for the US $2 million winner's purse. The race, organized by the U.S. Department of Defense's R&D arm—the Defense Advanced Research Projects Agency (DARPA)—was won by a Volkswagen Touareg SUV developed by a team from Stanford University, in California [see photo, "Winner"]. The Stanford car, dubbed Stanley, finished in 6 hours, 53 minutes—11 minutes ahead of the second-place finisher, one of two Hummers in the race that were rigged up by the Red Team from Carnegie Mellon University, in Pittsburgh. The outcome of the race, known as the Grand Challenge, showed just how far autonomous vehicles have come in a year. No one claimed the $1 million prize offered by DARPA in 2004. That year's winner—if you could call it that— hadn't gone 12 km before it skirted the edge of a cliff so closely that it got stuck. Its wheels continued to spin until one of the tires caught fire and the vehicle had to be deactivated remotely. Only two of the race's other 14 entrants passed the 2-km mark [see "Sand Trap," IEEE Spectrum, June 2004]. Explaining the vast improvement over last year's pitiful showing, a Stanford engineering school spokesman said: "The robotics community has learned a great deal about how to make cars drive themselves. In fact, artificial intelligence was employed in Stanley's programming that allowed it to continually learn during the testing conducted in the months leading up to the race." DARPA issued the challenge as a way to help the Defense Department meet a 2015 deadline for making 30 percent of the U.S. military's land vehicles autonomous. Unmanned vehicles could prove valuable in combat zones such as Iraq, where hundreds of soldiers and civilians have been killed or maimed by explosive devices planted on roadbeds.