Better Fuel Economy Does Not Preclude High Performance

Special Coverage

SAE World Congress

DETROIT – With all the renewed pressure on fuel economy, will auto makers still be able to offer consumers high performance?

The answer is a resounding “Yes.”

All it takes is more technology and an even stronger focus on cutting costs and weight, concludes a panel of experts at the SAE International World Congress here.

Thirty years ago, the idea of improving fuel economy and lowering emissions while simultaneously boosting performance would have been deemed impossible. Considering fuel economy has plateaued in the U.S. since 1985, skeptics might think it still is.

However, with one example after another, representatives from BMW AG, General Motors Corp., Mazda Motor Corp. and Aisin World Corp. of America demonstrate they already are achieving this goal with the use of advanced combustion technology, hybrid-electric vehicles, new transmissions and other powertrain improvements.

The only one to throw cold water on the optimistic mood of the panel is David Friedman, research director for the Union of Concerned Scientists, who suggests it is time engineers begin focusing purely on improving fuel economy instead of trying to do both.

Larry Nitz, executive director-hybrid technology, GM Powertrain, says while average fuel economy numbers have been flat since the 1980s, engineers have not been idle. Engine power has soared 70% and acceleration is considerably better, even as vehicle mass has increased.

Efficiency, when measured in terms of “ton miles to the gallon” has actually improved substantially, he says.

Nitz stresses hybrid-electric technology is an easy way to continue delivering performance, along with fuel economy, for consumers who demand both. He says GM’s Saturn Vue Greenline HEV gets better fuel economy yet accelerates faster than its non-HEV sibling.

Wolfgang Epple, BMW vice president-hybrids, points out the auto maker’s current 3-Series has 57% more horsepower and 17% better acceleration than a 3-Series from several generations ago, while still providing 31% better fuel economy and 95% fewer emissions.

Epple adds that better engine combustion with improved injection and valvetrain management will yield more gains in the near future.

HEV technology, he says, can add another 3% to 15% improvement in fuel economy, while still adding to overall performance.

Nobuhiro Hayama, Mazda managing executive officer-R&D quality & powertrain development, emphasizes new technologies such as direct injection combined with turbocharging can yield enormous benefits, allowing auto makers to obtain higher horsepower from engines that are smaller and more efficient.

His example: Mazda’s award-winning direct-injection, turbocharged 2.3L 4-cyl. mill used to power everything from the MazdaSpeed3 “hot hatch” compact to the Mazda CX-7 cross/utility vehicle, which produces as much as much as 119 hp per liter while still delivering excellent fuel economy.

Don Whitsitt, executive vice president of Aisin America, adds the Lexus GS 450h to the econo-performance list, pointing out that it has both better acceleration and fuel economy numbers than the non-hybrid Lexus GS 350 sport sedan.

Transmissions with more speeds, such as the 8-speed automatic Aisin supplies Toyota Motor Corp.’s Lexus LS 460, are another way to provide improved fuel economy and performance, Whitsitt says.

One of the few issues left unresolved by the panel is raised by the Union of Concerned Scientists’ Freidman, who asks when and if the continuous quest for more and better performance should be abandoned in favor of more aggressive fuel-economy goals.

Most of the panelists suggest that is an alternative U.S. consumers currently are willing to accept.

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