Instead, automakers are starting to switch to eight-speed automatic transmissions that offer better fuel economy without a big cost penalty.
As is customary with new technology, these advanced transmissions appeared first in luxury sedans. The BMW 7 Series and Audi A8 use eight-speed gearboxes designed by ZF Group, while the Lexus LS sedan features an eight-speed built by Aisin AW Co.
Now eight-speeds are filtering down to mass-market brands.
In North America, the turning point came in June when Chrysler adopted ZF's eight-speed automatic. Chrysler will spend $300 million to build the gearbox in its Kokomo, Ind., plant, which will begin production in 2013.
Chrysler says that all of its brands will get the new transmission. Since it is designed for longitudinal powertrains, the eight-speed is likely to be used in the Chrysler 300, the Jeep Grand Cherokee and the Dodge Charger and Challenger.
ZF says its new eight-speed transmission improves fuel economy by 6 percent compared with a six-speed automatic.
The ZF-Chrysler deal "was an eye-opener for many people," said Robert Blakely, director of marketing for the drivetrain systems group at BorgWarner Inc., a major producer of transmission components.
Noting ZF's reputation for high prices and high quality, Blakely called the ZF-Chrysler deal "a watershed event."
With Chrysler and Ford Motor Co. upgrading their gearboxes, it is safe to assume General Motors Co. will do likewise.
In August, GM announced a joint venture with Chinese partner SAIC Motor Corp. to develop a dual-clutch transmission for four-cylinder engines. GM said the gearbox will improve fuel economy up to 10 percent over a conventional six-speed automatic.
That same month, enthusiast Web sites speculated that GM also may be developing an eight-speed automatic. The rumor gained traction after the automaker registered a trademark for the phrase "8 Speed."
What does the future hold? Mercedes-Benz is rumored to be developing a nine-speed automatic (dubbed 9G-Tronic) that will debut in the 2012 S Class sedan.
At some point one might ask whether advanced transmissions offer enough performance to justify the cost. So far, automakers clearly believe the answer is yes, says Edmunds' Brauer.
According to Edmunds, 28 models equipped with dual-clutch transmissions are available to U.S. consumers in the 2011model year, up from 14 models in 2007. And 19 models are equipped with eight-speed automatics, up from just one in 2007.
"Everyone is looking for the most efficient transmission," Brauer says. The new CAFE standards "play a huge role."