General Motors is counting on four core strategies to meet rising fuel-economy standards: weight reduction, advanced powertrain technologies, more efficient integration of vehicle components and subsystems, and better aerodynamics.
Of those methods, aero is by far the cheapest to implement. So GM has decided to spend some money to make it quicker and easier to achieve slipperier designs.
At its main technical campus near Detroit, GM has opened a $30 million wind tunnel that blasts small-scale vehicle models with winds up to 155 mph. The clay models are just 40 percent the size of the real things, but have working suspensions and realistic but scaled-down engine blocks and underbodies made by 3-D printers. The goal is to enable designers to fine-tune vehicle shapes faster to reduce wind drag.
GM increasingly is emphasizing aerodynamic efficiency in its designs, said Scott Miller, director of GM's CO2 strategy. For example, the sleek 2016 Chevrolet Malibu that arrives in dealerships next month boasts an improved drag coefficient of 0.29, in the neighborhood of some electric vehicles (the 2016 Chevrolet Volt's is 0.285).
The 35,000-square-foot tunnel has a 1,100-hp fan that uses 18 carbon-fiber blades. It's just a few hundred feet from GM's 35-year-old full-scale wind tunnel, which will undergo a major renovation next year.