Chevy Technology Series Part 5: Exterior Design
FOR TODAY'S CHEVY, BEAUTIFUL DESIGN ISN'T JUST SKIN DEEP
When Noah Webster published his first dictionary in 1806, A Compendious Dictionary of the English Language, he defined design as “to purpose, intend, plan, devote.”
More than 200 years later, Webster’s definition sums up Chevrolet design remarkably well. Each vehicle is the result of criteria conceived in advance, to a purpose and to a specific intent, whether it be exceptional fuel mileage, like Volt, exceptional high-performance characteristics, like Corvette ZR1, or — like the vehicles in between — to be exceptional all-around athletes.
Additionally, the amount of planning is comprehensive and all-inclusive, because it’s mandatory that every aspect of a vehicle be integrated into the design, from the powertrain to the greenhouse to the wheelwells. And the devotion to perfection at Chevrolet design, both in the U.S. and the 10 design centers working in concert around the globe, is all-encompassing.
There was one word Webster left out that applies undeniably to Chevrolet design: passion. Join us for a walk through the Chevrolet design process, and you’ll see that passion, beginning with the initial drawing of a new car or truck and ending in the completed project.
In 1937, Chevrolet received its own dedicated styling studio. Chevrolet models then were typically clean, functional designs, with the flair largely reserved for GM brands like Cadillac. That changed in 1953, when the Chevrolet Corvette was introduced at the GM Motorama show: Chevrolet design would never be the same. Before the end of the decade, Chevrolet design would stun the automotive market with groundbreaking 1955, 1956 and 1957 coupes, sedans and convertibles, topped with signature vehicles like the Nomad wagon and the El Camino. In late 1955, Chevrolet debuted an all-new breakthrough pickup truck design that featured the industry-first “wraparound” windshield, as well as a V6 engine and a 12-volt electrical system.
Finally, vehicles with genuine style and personality — on both the car and truck side — were available to any customer. Since then — be it with generations of Corvette, Camaro or Silverado — Chevrolet has remained committed to delivering a measure of design personality with every new product.
It Begins with an Idea
Kirk Bennion, exterior design manager for Chevrolet Corvette and Camaro, admitted that it’s true: Most fledgling car designers start out as the kid sketching hot rods in study hall. “But the ones we’re looking for at Chevrolet,” he said, laughing, “are the ones sketching cars in the margins of their notebooks in math and geography, and social studies too.”
Today, Chevrolet stylists work in concert with engineers to serve multiple masters — with each design, they must consider safety, weight, fuel economy, acoustics, airflow and a host of other requirements. Even climate must be considered: Will panel gaps and windshield angle and door seals remain consistent and functional in very dry and very rainy conditions, and in extreme heat and extreme cold? That’s tested in a “climatic wind tunnel” — a virtual torture chamber for any vehicle design.
Great Aerodynamics Doesn’t Just Happen
Aerodynamics is one aspect of design that is just as important to ultimate performance cars, like Chevrolet Corvette, as it is to cars that emphasize mileage, like Chevrolet Volt. The more easily a vehicle can cut through the air, the less power it requires to maintain a certain speed.
Working closely with aerodynamicists in the wind tunnel, Volt design and engineering teams developed one of the most aerodynamic vehicles in Chevrolet history. By reducing the energy needed to overcome air resistance, Volt aerodynamicists contributed an estimated 8 miles of electric range and 50 miles of extended range based on the EPA Highway drive profile. The rounded and flush front fascia, tapered corners and grille enable air to move easily around the car, and in the rear, sharp edges and a special spoiler manage airflow, while an aggressive rake of the windshield and backglass also help reduce turbulence and drag.
Techniques learned on Volt benefit vehicles like the 2013 Chevrolet Malibu. How did that happen? Not by accident. Outside rearview mirrors are designed to deflect wind, without upsetting overall airflow. The rounded front corners of Malibu channel air smoothly along the sides of the body. Shutters in the lower grille opening on Eco models open and close automatically to maximize aerodynamic efficiency.
This increases cooling airflow to the engine under certain conditions, such as under high engine loads at low speeds, and reduces aerodynamic drag when extra cooling is not needed. All these features and more were tested both on the computer, using computational fluid dynamics, then by over 400 hours spent in the wind tunnel.
“Negotiating the competing interests of design, manufacturing and vehicle engineers — all of whom have different goals for an individual part or the vehicle’s overall design — can be inspiring,” said Suzanne Cody, Malibu aerodynamics engineer. “But we all have a common goal: to give Malibu customers around the world Chevrolet’s most fuel-efficient midsize car ever.”
That goal was met — Malibu Eco with eAssist technology has an EPA-estimated fuel economy of 25 MPG city/37 MPG highway. Malibu is a car with a global footprint — it will be sold in nearly 100 countries, on six continents.
“Ultimately, we were able to design Malibu so that drivers around the world would benefit from its aerodynamics,” said John Bednarchik, lead aerodynamics engineer for Malibu. “It’s amazing when I think that the design decisions we made in the wind tunnel could save Malibu buyers around the world hundreds — if not thousands — of dollars at the pump.”
Safety Dictates Design Too
“Safety is paramount,” said Bennion. “Good front crashworthiness, for instance, partly relies on factors like how much front overhang we have, how much bumper offset, what sort of structure you have around the lamps.”
It involves, Bennion said, “the fundamental shape of the car, and that work is done early on. Again, you must achieve a balance. Safety and passenger protection must be optimized, but you don’t want to make the car bigger or heavier than you have to. Safety, obviously, comes first and we’re always looking to optimize that with the best power-to-weight ratio as well.”
Designers must also take into account what can and can’t be done with both external and internal construction materials. What can and can’t be done with metal or fiberglass? Can a design’s curves be built to be repeatable and high quality? What about the shape and angle of a windshield and side glass?
The Chevrolet Cruze, for instance, was designed with precision-related requirements that challenged engineers and assembly plant workers. The Lordstown, Ohio, assembly plant body shop was retooled with the latest in body-framing and welding equipment to optimize the manufacture of a solid body structure — that structure means minimal production variance and repeatable gap tolerances of just 3 millimeters or less between the majority of exterior panels.
Designing for the Future
In the past 15 years, Chevrolet designers have adopted more and more sophisticated computer-related aids, and that will progress. “Virtual” reviews have helped streamline the process — multiple headlamp and taillamp options can be considered at once, for example, both dark and illuminated. “Rapid prototyping,” using laser technology and photochemistry, helps designers develop scale models of components or entire vehicles in much less time than it took only a few years ago.
Still, Bennion said, “computer programs are great for early development and the final stages of a design, but you can’t use a computer for every job, any more than you can work on your car using only a crescent wrench. There’s still an appreciation for hands-on design and sculpting, and that won’t change. We’ll continue to enhance all the tools we have, but we won’t eliminate any of them.” Despite the sophistication of the modern Chevrolet, “we’ll continue to emphasize the art of design.”