Automakers battle for efficiency

Where automakers once competed against each other to see which engine could crank out the most power, new federal regulations on fuel economy and tailpipe emissions have brought such battles nearly to a screeching halt.

With the manufacturers facing a deadline of 2016 to increase their fleets' corporate average fuel economy — also known as CAFE — to nearly 35 mpg, their designers and engineers have changed the focus to concentrate on efficiency, not performance.

Automakers say they're confident they'll meet the deadline, and they also are reassuring worried consumers that the new regulations don't mean everyone soon will have to buy sardine-can-size cars.

“We feel comfortable with being able to meet the regulations, which begin going into effect in 2012,” said Tracy Woodard, director of governmental affairs for the Tennessee-based Nissan North America Inc., which later this year will become the first automaker to roll out a mass-production all-electric car, the Leaf.

“The recent rule making (by the Obama administration) covers both greenhouse gas regulations from EPA and CAFE standards from (the National Highway Traffic Safety Administration),” Woodard said. “Nissan was supportive of the one national standard and will be looking at the range of technologies available to us.”

While the small car and the four-cylinder engine are going to play key roles, they're not going to solve the fuel-economy problem by themselves, automakers and analysts say.

There are more efficient six- and eight-cylinder engines in production or under development as well, so vehicles that require more power — such as pickups and large family haulers — won't have to give up performance in the quest for mileage, said Charlie Klein, director of mass energy and aerodynamics engineering for General Motors Co.

Advances such as direct fuel injection, variable valve timing, turbochargers and automatic transmissions with six or more forward gears can help give a four-cylinder engine the power of a V-6, or a V-6 the power of a V-8.

Technology such as GM's active cylinder management — which cuts out half of an engine's cylinders during highway cruising to decrease fuel consumption — can give a powerful V-8 the fuel economy of a V-6 or even a four-cylinder, Klein said.