Half a century ago, automatic transmissions had two or three speeds, and progress has come slowly since then.

Today, many cars are still sold with four-speed automatics, though five- and six-speeds are the new normal.

Next year, Chrysler will introduce eight-speed automatics on its full-size rear-wheel drive sedans, the 2012 Chrysler 300 and 2012 Dodge Charger--giving its mass-market cars the number of gears offered by such luxury marques as Audi, BMW, and Lexus.

The payoff is purely in gas mileage.

Chrysler said today it expects its 2012 sedans to return an estimated 31 mpg on the highway, and 19 mpg on the EPA city cycle, when fitted with the company's 3.6-liter V-6 engine, the new eight-speed automatic, and rear-wheel drive. That's likely to come out to a combined rating around 23 mpg.

2011 Dodge Charger

2011 Dodge Charger

That's a notable increase over the 2011 models, which are rated at 18 mpg city, 27 mpg highway, for a combined rating of 21 mpg. There's also a Sport mode for spirited driving, though the cars will almost surely default to the standard higher-mileage mode.

The new eight-speed automatic is likely to spread across the lineup of Chrysler, Dodge, and Jeep vehicles that use the 3.6-liter V-6, a new mainstay engine for Chrysler that replaces various older V-6 engines.

Expect to see it eventually in the Jeep Grand Cherokee, Dodge Durango, and probably even in some models of the company's Ram pickup trucks.

The new eight-speed automatic was designed by German firm ZF, and will be built in Indiana starting next year.

But that's hardly the end of the automatic-gears arms race. Chrysler has already announced it will fit a NINE-speed automatic--the world's first on a production car--to its next generation of front-wheel drive mid-size cars.

It's all in service of boosting fuel efficiency and doing more with less.

[Detroit News]


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