Automotive designers should be commended for doing their part to forestall depletion of the precious natural resources necessary to drive internal-combustion engines as we know them today.
Aerodynamicists have saved untold barrels of oil purely by styling hybrid-electric vehicles with smooth surfaces, steeply raked windshields, sleeker mirrors and uncluttered underbodies, allowing them to slice through air like a hot knife through butter.
But the language of aerodynamics is the same in Japanese, English, German or French, so it should not be surprising the world's most fuel-efficient vehicles look alike.
Ever since the arrival in the U.S. of the Honda Insight HEV in 1999, vehicles dedicated to maximizing mileage have embraced jellybean shapes to minimize drag.
The poster child for this uninspiring shape, often castigated by bloggers with strong opinions about how a car should look, is the Toyota Prius. The fuel-sipping sedan won't win any beauty contests, but with three generations as the world's best-selling HEV, the Prius' design can't be wrong.
At the recent North American International Auto Show in Detroit, Ward's editors asked the world's top designers a few simple questions: Must high mileage go hand-in-hand with bland design? Is it not possible to achieve edgy good looks while creating a shape that still manages a low coefficient of drag?
From a styling perspective, HEVs today fall into two categories. There are the hybrid versions of vehicles already on the road, such as the Toyota Camry, Honda Civic, Nissan Altima, Chevrolet Malibu, 2-mode Saturn Vue and, soon, the Ford Fusion/Mercury Milan.
These vehicles blend in like fans at a football game. But the Prius and Honda's all-new Insight are the face painters in the crowd, the vehicles that call attention to themselves as purpose-built hybrids. Their unique designs remind motorists that better mileage is possible. When fuel prices surpassed $4 a gallon last summer, Prius owners were eyed with envy.
When fuel prices suddenly fell, however, that envy turned to scorn from Americans who remain passionate that cars are not merely modes of transport but also a means of self-expression. Does a Prius owner have much in common with someone who lovingly washes his Dodge Challenger, BMW 335i or Mazda RX8 every sunny weekend?
Surely a happy medium is attainable, and at some point (we can hope) designers will break the mold with hybrid styling and produce vehicles that stoke the passions of those who want both expressive design and the best fuel economy.
“You can do a vehicle that's got great aerodynamics and still has a terrific style,” says Ed Welburn Jr., vice president-global design for General Motors Corp. “I won't accept anything less than that in the work we do.”
Aerodynamics are the key to boosting mileage in an HEV or electric vehicle. “Not good aero, but great aero,” Welburn says. “You've really got to get the drag down to extend the range.”
The 2-mode Chevy Tahoe Hybrid, although it still looks like a standard Tahoe (except for the massive badging that runs the length of the rocker panel), actually underwent intensive aerodynamic work in the wind tunnel that resulted in redesigned headlamps and fascia, as well as the addition of gills in the front air dam for better air flow.
“That truck has the same coefficient of drag (0.34) as the C4 Corvette,” Welburn says. “But it's faithful to where the Tahoe needs to be — big, strong, bold. OK, it's not as low drag as a Prius… but compared to every other fullsize SUV, it's really low drag.”
GM excited the hybrid world when it introduced its sleek Chevy Volt extended-range electric vehicle concept at the 2007 Detroit auto show.
But when the production version debuted more than a year later, it was rounder, taller and depressingly less sporty than the concept. It now bears more than a passing resemblance to the Prius.
The Volt's edginess is gone, and merciless bloggers find the car revolting, comparing it to cottage cheese. The production Volt, in their eyes, demonstrates why GM should be allowed to fail.
At this year's Detroit auto show, GM once again set hybrid hearts aflutter with the debut of the Cadillac Converj concept, an extended-range EV deploying the same Voltec propulsion system as the production Volt, slated to arrive in late 2010.
GM says the Converj, with its 4-cyl. gasoline engine, electric-drive unit and lithium-ion battery, can drive up to 40 miles (64 km) without using a single drop of fuel.
But a vital difference between the Volt and Converj is the styling. While the 4-door Volt is practical and more spacious, the coupe is angular, wedge-shaped and downright sexy, borrowing generously from Cadillac design cues, particularly in the front end. The Converj accommodates two in the back seat, but it's an awfully cramped back seat, like any credible sports car.
GM hasn't given the green light for Converj production yet, but skeptics surely expect it to follow the same disappointing path as the Volt — from beautiful concept to frumpy production model, with better aerodynamics.
Welburn promises that won't happen with the Converj.
“It's strictly a concept, but if it went into production it would look very much like this,” he tells Ward's, motioning to the concept. “A lot of aero work has been done on it. The decision on the design theme we went forward with was based on aero.”
Many GM concepts over the years have gone without extensive wind-tunnel testing, unlike the Converj, Welburn says. “We've got a real aero champ here.”
GM isn't disclosing the drag coefficients for either the Converj or Volt, but Welburn says the production Volt is 30% cleaner aerodynamically than the concept.
Toyota takes exception with those who find the Prius stylistically challenged. “I'm sure a lot of people look at Prius and think it's sexy,” says Jim Lentz, president of Toyota Motor Sales U.S.A. Inc.
He says aerodynamics are critical to the new '10 Prius achieving a combined estimated fuel economy of 50 mpg (4.7 L/100 km).
Toyota says the new Prius, which arrives this spring, has the cleanest aerodynamic profile of any mass-produced vehicle in the world, scoring a drag coefficient of 0.25, compared with 0.26 on the outgoing model. (The new Honda Insight scores 0.28 on the drag-o-meter.)
Even the Prius' wheelhouse liners and shape of its wheels were influenced by wind-tunnel testing.
“Today, this is what we feel is the best aerodynamic package available,” Lentz says. “But I'm sure as we continue to do research, we'll find there are tweaks and changes that will make it even more aerodynamic. So I think you will always see cars that look very different.”
Kevin Hunter, president of Toyota's Calty Design Research arm, says the Prius' hatchback body style and gradually descending roof give the car its own identity, while enhancing aerodynamics significantly.
“I really think the centerline profile on Prius is quite a bit different than what Chevy has with the Volt, in its silhouette profile,” Hunter says. “And I think you'll notice we've got large lower intake and smaller intake slots up high (in the grille). That's a trend you're going to see too, because it helps to take in air underneath and it reduces drag.”
Hunter disputes claims by some auto makers that round corners up front are better for aerodynamics.
“We're saying crisp corners are better for airflow,” he says. “We're trying to keep air attached to the body as it moves back, and then at the rear having edges because it cuts off cleanly.”
Wind-tunnel testing does not come cheaply, another reason why most HEVs are not profitable. At the upper end of the market, auto makers can afford for their concepts to spend a little extra time in the tunnel.
Take Fisker Automotive Inc., a California-based privately held auto maker that plans to sell its first Fisker Karma for a cool $87,900 beginning this fall. The 4-door plug-in luxury HEV oozes sultry good looks and would fit right in at the finest country clubs, while achieving 100 mpg (2.3 L/100 km) and a drag coefficient of 0.31.
At this year's Detroit auto show, Fisker unveiled the production Karma, as well as a convertible version with a shorter wheelbase. The droptop will go on sale in 2010, but pricing has not yet been set.
Fisker Automotive CEO Henrik Fisker has strong opinions about the state of HEV design.
“I haven't read any rules anywhere that plug-in hybrids or electric cars have to be boring or look like jellybeans, so I'm ignoring it if there are some rules,” says Fisker, who led design for the Aston Martin brand before leaving in 2004 to start his own car company.
“For me, I see a vision of the future which is exciting, sexy cars again, which I think was slipping away a few years ago,” Fisker tells Ward's. “I think, because we are a small company and probably because I'm a designer leading it, we're going extreme when it comes to design. I truly believe a really good-looking car sells.”
For the Karma buyer, styling will trump functionality. “We're not going to be the one with the most legroom in the rear,” Fisker says. “We'll leave that to some other companies, but we are going to be the one that has the most dramatic and sexy proportions. No.1 for us is not how much room is in the back or how big is the trunk.”
Auto makers on a tighter budget, however, will face hurdles, because every incremental gain in a vehicle's drag coefficient takes money out of the product-development budget.
Peter Schreyer, chief design officer at Kia Motors Corp., says he dealt with the same problem while working at Audi AG.
“It's not as if you can go from a drag coefficient of 0.27 and then the next one to 0.25 and to 0.22 and then to 0.17 and then to 0.12,” Schreyer says. “Every notch is really difficult to achieve.”
Ralph Gilles, vice president-design at Chrysler LLC, is anxious to dispel the notion that the Prius' shape is the end-game for the design of alternative-powertrain vehicles.
“People have identified that as being the look of efficiency, so to speak,” Gilles says. “We're trying to go at it a little bit differently. You can still be emotionally attached to your vehicle and be completely responsible.”
Gilles admits there are limitations to focusing intently on aerodynamics, but he welcomes the challenges and says nearly every external surface must be analyzed for improved drag.
At this year's Detroit show, Chrysler unveiled the 200C EV electric-drive sedan concept with a dramatic wheel design that improves aerodynamics.
Chris Bangle, head of BMW Group design, says platforms dedicated to alternative powertrains, such as the Prius or Volt, represent the best hope for dramatically new designs.
“Trying to package three different types of drivetrains into one type of a new vehicle (is the) worst-case scenario,” Bangle says. “As long as you have to deal with a lot of conventional drivetrains, things are going to (remain) very conventional.”
Audi's emphasis on aerodynamics can be seen in the current A6 sedan, with a sharp-edged back end that replaced a beautiful and curvaceous tail on the previous-generation A6.
Stefan Sielaff, head of design for Audi, considers the new shape to be less elegant but more functional by managing airflow to provide additional down force for the back end of high-powered versions of the A6.
Audi is world-renowned for its styling, but it has yet to introduce an HEV. It sold the pint-size, fuel-efficient A2 in Europe, but the program failed and the vehicle was discontinued in 2005, after six years on the market.
A hybrid-electric version of the Q5 cross/utility vehicle is expected in late 2010 or 2011, with a gasoline engine.
Asked what a dedicated hybrid from Audi might look like, Sielaff says it would be angular and borrow some of the A2's design cues.
“For sure it would not be a jellybean,” and it would take advantage of sharp lines, great aerodynamics and advanced lightweight materials, he says.
In the future, the state of HEV designs will depend on the willingness of consumers to drive an environmentally advanced vehicle that stands out in the crowd.
“I'm sure the people who want to make a political statement (by driving an HEV or EV) don't really enjoy driving a car from an emotional point of view,” Sielaff says.
He hopes a dedicated HEV from Audi would let people make that same political statement, while fostering an emotional attachment with great design.
“Then we will have done a super job,” Sielaff says, “and we've given the customer the best of both worlds.”
— with Christie Schweinsberg and Eric Mayne
Chevy Volt: Bland Design, Bold Engineering
Insight Runs New Kind of Race — And Wins
Next-Gen Prius Debuts With Estimated 50-MPG Rating
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