The White House's goal of a 54.5 mile-per-gallon average fuel economy could inspire innovation, but it could also lead to safety and costs trade-offs, one industry expert warned last week. "Putting the 54.5-mpg target out there is good," said Sandy Munro, CEO of Munro & Associates Inc., a consultant doing cost studies on the subject for the Environmental Protection Agency (EPA). "Engineers always need a challenge. But the question is, what are you willing to give up to get there?"
In an interview with Design News, Munro cited a multitude of ways to boost America's corporate average fuel economy (CAFÉ). Big ticket items include hybrid vehicles and pure electric cars, but Munro told us lawmakers and auto manufacturers are talking about many other possibilities, too. Those include lightweight materials, such as carbon fibers, magnesium, and titanium. Also under consideration are engine enhancements, such as variable valve timing, reduced displacement, and turbochargers. Transmissions will continue to increase the number of gears -- with automakers offering eight- , nine-, and 10-speed models -- and some transmissions may start using different case materials in order to reduce weight.
Munro also cited vehicle interiors as a place for innovation and weight reduction. He said the amount of wires and wiring harnesses need to be reduced. Heavy components, such as seats and instrument panels, must also be substantially redesigned to employ lighter materials. "People are always looking at the powertrain and body," he said. "But we've got to look at the whole picture, and that includes the interior."
The simplest way to reach 54.5 mpg, however, might just be size reduction. Smaller, lighter vehicles offer a fuel efficiency boost that is roughly proportional to the reduction in mass. "A mid-size car won't have the same volume that it has today," Munro said. "You'll get your groceries in there, and you might get your golf clubs in there, but it's not going to have the same amount of volume it has today."
Innovative new materials will also raise costs. Munro said that aluminum and steel skins for today's conventional vehicles cost about $0.30 and $0.55 per pound, respectively. In contrast, magnesium runs $2.20, titanium is about $35, and a carbon fiber skin is roughly $40 to $50 per pound. While titanium and carbon fibers offer the opportunity of using less material by weight because of their lower density, the cost differences would still be significant, Munro said. "Hitting 54.5 miles per gallon is possible, but it comes at a price," Munro said. "It goes back to whether the general buying public is willing to put up the cash."
A 2011 study by The Center for Automotive Research indicated that proposed regulations could drive up the cost of new vehicles by as much as $11,000.